That's odd that it would take so much time to come back unless it's a network issue. When I had my G2 using WiFi it would often need a reboot to reconnect after a router reboot but never again after I switched it to Ethernet. It would take about 3 minutes after a reboot to come back online. I had it set up to reboot remotely which, with your P2 in a hard to reach place, you might find convenient as well.
Plug the P2 and the PLM into a small, non filtered power strip like this one:
amzn.to/3PgHuS2
Then plug it into an X10 Appliance Module or an Alexa capable module and make the reboot easy from anywhere!
One thing I forgot to mention earlier is to try logging out of the app and then logging back in if the app doesn't see the P2.
To log out, tap the menu icon in the upper left corner, then tap on your name at the top and scroll down to the bottom to find the big red logout button.