The last update as you can see:
https://github.com/OpenSprinkler/OpenSprinklerGen2/commit/3f32a564e278f32ebfd3aae7efa15769f10e83f2
is 12 days ago, which means most likely you have the previous version, so an update is highly recommended.
When LCD shows ‘Connecting…’ it IS making a DHCP request and waiting for response to come back. So as I said, if for some reason, the bug was triggered and the controller gets stuck in the connecting loop, that can well explain the DHCP burst.
If you want to try, you can set the controller in static IP, which should bypass the DHCP burst.