Hello Again!
After many , many hours of loading save games and mod testing, I found out that there is an issue with Bobs Power Poles from https://mods.factorio.com/mod/bobpower
When placed, the poles drop their connections, and even if you try to add it with the cable connector tool (alt+c), it does create the connection , but the moment you move your mouse, no sooner, no later, it disappears again.
This is only with bobs, vanilla poles seem to work fine.
Also logic red/green cables are also fine with both vanilla and Bobs poles loaded.
I dont file this under bugs because I am not sure this mod is supposed to support Bob mods.
Recorded in Sandbox with only offical DLCs, Bobs and Grid:
Left side are Vanilla , right are Bobs poles
https://imgur.com/o2QpskX