paulbates

You need to know how to log when you have an plugin issue and developer asks you to send them a log. What's important to know about that is:
you go to the dashboard in pg3x go into the individual plugin itself click details Click log Click "debug" from the list Do the steps that recreate the error you are seeing Click download log package Send that zip file in a message to the developer
 
There's a new wrinkle in the Session and Session Verbose options. I'm going to not select those unless instructed to by the developer.

Do not buy another license. Submit a ticket and it will get fixed.

Take a look at the solution, here
 

Right click on Deck Lights and pick "Restore Device". Compare and test again
An additional method is to factory reset Deck Lights, that will clear all links, and then "Restore Device".

It does... plugin = polyglot pg3.  You posted under eisy so I assume you have that, if so you already have polyglot installed.
There is a learning curve for sure
Another option: if you have the UD portal, use the UDM mobile app and notifications can be sent to it relatively easily, probably not a big leap from your att texting, making some mods to programs. You won't need polyglot. This may be the place to start.

I don't believe there is a time out, per se. It's not designed to be left running, when you're done working, close it down. 
Having said that, I forgot to shut it down sometimes and it will run for days before I notice. But I try to remember to shut it down

You don't have a ton of devices so starting over is do-able. Give this a read first and use it as a guide
I'd print out yourf programs you have for a reference.
One at a time, delete each device from the ISY, making a list of them as you go so none are forgotten. WRITE DOWN THE INSTEON ADDRESS FOR EACH BEFORE YOU DELETE - 11.22.33 format Reset the PLM Pick delete Modem (PLM) from the File menu and complete prompts Reset the PLM - Un plug, wait 5 seconds, replug while holding the set button until it beeps Unplug the PLM wait 5 seconds and plug in Unplug and replug the eisy, log back in to iox Go to Tools/Diagnostics/PLM info status, look for it to say connected Repeat 3 and 4 above again, even a few times, until it says connected Do not try to add the PLM as a device to your eisy, iox does that on its own One at a time add non-battery devices Go to each non-battery device, unplug, replug while holding the set button For switches, pull out the air gap, wait 5 seconds, then press in and hold In both of the above cases, Wait for the beep  Pick New Insteon Device from the linking menu be sure to pick "remove all existing links" One at a time add battery devices Go to each battery device, press and hold the set button until it beeps In both of the above cases, Wait for the beep  Pick Link a sensor from the linking menu be sure to pick "remove all existing links" If you get stuck on one, move on to the next.
Test everything out. 
You will have to update programs

It would be the same approach as your other servers and Rpis. SSH in to the eisy, create python or other method to detect the UPS's mode and issue command line to shut it down. I google searched "shut down freebsd" and specific command line examples were returned. 

Go to the My Programs folder and right-click on it. Pick Find/Replace near the bottom and select the device to find instances of it. 

I didn't read the entire thread, so if you haven't tried, in this order:
Unplug / replug PLM. Restart eisy, check again Factory reset PLM, check again, if connected, restore modem  
 

(2) Haven't tried it on the eisy, but give this thread a try. Looks like variable substitution might break it. 
I used HAD pages served from my ISY's web server and accessed them through the portal, but many years ago.
 

So... reread...  You'll want to do it this way
New Program - [ID 0045][Parent 0001]
If
   - No Conditions - (To add one, press 'Schedule' or 'Condition')
 
Then
        Repeat Every  1 hour 
           Set 'ERV'  On
           Wait  20 minutes 
           Set 'ERV' off
 
And set it so it runs at startup

There are a few potential trip wires
If you can "hold your breath" till you get the new plm, I would do that and not reconnect the old isy... You have to reprogram all insteon devices (restore plm) to your old isy, and then turn around and do it again for the eisy when the new plm arrives When you get the new plm, my suggestion is to restore your eisy to the last eisy back before you had plm problems, so you didn't restore bad insteon data to the new plm

Here's a screen shot of all of the values it provides
https://forum.universal-devices.com/topic/43016-if-day-of-month-x/?do=findComment&comment=379456
 

Since it programs can be accessed in UDM and working... to me it points to the java installation on the computer.  Do you have a lot of programs and variables. This is an older recommendation for t something that has the appearances of a memory problem

Java runtime memory (when Admin Console is very slow to respond)
-      If the admin console is slow to respond, it is likely you need to increase the amount of memory allocated to the Java runtime (JRE).
-      Open the Java Control Panel, select Java tab, press View button, then add or modify the Runtime Parameter -Xmx to the following:
o   -Xmx512m
-      Press Ok to close the window, then Press Apply to save the changes

The ISY's use of the network is very limited (doesn't stream) and only connects at 100mb, so an ET / WIFI bridge should work fine. Like most things network, you'll get what you pay for, eg get a highly rated product vs cheapest. 
Other ideas:
If he has some kind of cable service providing streaming services to his tv vs logging the tv in directly, the boxes providing the streaming to the tv sometimes have ET ports in the back
  I usually have my previous router hanging around after I upgrade. Some routers can be configured in bridge mode: You log the router into the campus wifi, and plug the ISY in to one of its ET ports.

The event viewer, set to level 3, is different than the log and will show detailed Insteon traffic (or lack of it) to help figure out what's going on.
Tools->Diagnostics->Event Viewer ... set to level 3 at the bottom and repeat your tests, post that back here by Saving the Log to File with a description of what part you were doing each test
Did you try the "restore device" on one of the problem devices?

I would pull the plug on the eisy, plug back in

Too much "on time" or bad links could explain some of this. Just to clarify, the UDM app gets different results than the iox console and programs?
There's limited things that can be done:
You might have done this, but pull the air gap out, count to 10 and push back in to restart it If that doesn't do it, factory resetting the kpl and restore device which will replace the links table. I don't have any KPLs at this house but had them for a long time at my prior house and either air-gapping or  occasionally factory resetting and restoring helped. 

It's a climate type, and uses status:

Put one of them in linking mode, right click on it in AC and pick restore device. It's possible things got confused in the upgrade. If that works, continue on to the others that aren't workinkg

Me too. I don't have the distance requirement, but I have 4 temp / humid sensors buried in metal / stainless fridge/freezers and they work and show strong signals.
Like any technology, its been a learning curve to get yolink's way of thinking (like how long between temp/humdity update), but everything's working
I'm getting there. It is a great compliment to an Insteon power line solution.. they both do a great job of what the other doesn't
Yes... or learning to drive stick shift all over again 🤪😂

Unfortunately you are the victim of bad timing. On of the underlying pg3x support libraries changed (MQTT) and caused  new installs of of plugins to break. I see MQTT error messages in your error log above.
UDI will work to restore it tomorrow, read this thread
 

You can also simply right click and "copy" the entire program and then rename it and "remove" the if and replace it with what you want

Before giving the PLM an "all clear", how old is it. To complete your list of things, I would unplug it, wait 10 seconds and replug in, re-run your tests.