EDIT: Due to bone-headed-ness and less than perfect vision, I finally saw that the IP address' first "." was actually a ":" So problem solved - sorry for chewing up bandwidth and please disregard the below as it relates to the ELK issue.
So after banging my head against the wall and reading all sorts of cryptic instructions (some older, some newer apparently), I "updated packages" on the ISY config page and Voila - the node servers are connecting and showing up in IoP.
The nodes are populating in the case of Rainmachine and Kasa, but the Elk Node server only has one node, and it is just basically a connection verification - no zone status etc...
It is also showing (in IoP) "Connected" but the M1XEP status show "false", implying the Node server and the IoP are communicating, but the Node server is not getting through to the M1XEP (ethernet connection to ELK). I used the exact same parameters that have been in my old ISY for years - same ip, same password, same port...
Tried "add all nodes" in IoP (there are about a dozen listed), but nothing populated in IoP.
Any ideas from those that use an Elk?
Thanks for all the assistance!