Okay so after some testing it turns out it wasn't my ISY or my router but it was just a coincidence that both my Windows desktop and iMac both stopped responding to WOL packets at the same time. I tested by using a couple WOL utilities found at https://community.spiceworks.com/how_to/1543-troubleshooting-wake-on-lan-wol-with-third-party-tools
One utility is a WOL transmitter and the other one is a WOL monitor. I installed them on two different Windows machines on my network. For some reason when the utilities start they are set to port 4343. Since most WOL utilities use port 9 (including my ISY) I changed the utilities to use port 9. When i transmitted the WOL from one Windows PC the monitor installed on a different PC received the packet. I then used the WOL test function on the ISY and sent a WOL packet. The monitor client saw it so I knew the ISY and my network were fine.
I then checked out the Windows client that WOL stopped working on. I noticed that when I did a shutdown the network card went completely dark. This hadn't happened before. I tried multiple power setting changes on the PC, checked all CMOS settings, checked network card driver settings, and even turned off hybrid mode but a shut down is now completely powering off the nic. I've been running Windows 10 for a long time so I'm not sure what changed. Must've been an OS update or a nic driver update.
My fix. No more shutdowns, I just hibernate the machine as hibernation does not shut the nic off and still consumes minimum power. I'm guessing a similar issue with the iMac but haven't had time yet to research it.
If you want to use a WOL utility from outside your network on the internet such as the one within Teamviewer then you may need to set a static arp route on your ubiquiti router and forward port 9 from your WAN interface to the new static arp address. Pick an ip from your dhcp pool that you are not using. The Arp entry should look something like this (set protocols static arp 1.1.1.1 hwaddr ff:ff:ff:ff:ff:ff) 1.1.1.1 would be an unused address in your dhcp scope. Then forward port 9 to the same address you used instead of 1.1.1.1 in the arp entry. I believe WOL only uses UDP so you would only have to forward UDP on port 9 if you want.