Zend certified PHP/Magento developer

Troubleshooting TouchOSC remote to desktop connection

I can target and update layouts on my mobile TouchOSC app from the desktop TouchOSC Editor.
I have also confirmed that my desktop IPv4 address is correct and configured correctly in my TouchOSC mobile app under OSC connections – Host. ditto for outgoing and incoming ports.

However my mobile TouchOSC app cannot send messages to the desktop…or at least I am not receiving them. I also tried using the Protokol app but not receiving anything.
Most confusingly everything WAS working a few days ago. And nothing has change except for my desktop IP address on reboot.
I’ve also tried disabling any firewall. (Windows 10)
Can anyone suggest some good troubleshooting steps to try?

Should I be using an app like Wireshark to confirm my desktop is actually receiving the OSC messages?
Using the older mk1 version of TouchOSC
https://hexler.net/touchosc-mk1#downloads