High voltage hardware question

[mister_e]

Ground plane, ground/power routing, splitting power/digital/analog ground, PSU bypassing, PCB layout... tons of possibilities here.

Overloading PICoutput/PORT is still possible. The whole schematic and actual layout could be helpful.

[SOMRU]

Try adding an inexpensive small relay, or optocoupler, in parallel to the coil, then use the contacts as your signal source. Simple easy and I use this type of isolation in industrial welder controls.