Hmm, interference is certainly a possibility given all of the different systems going on in this house plus really old wiring. But whatever the source of the problem, I think I need a new solution for them.

I’ve been poking at this some more myself and am wondering if shelly relays are the answer. Put one at the light to turn it on and off and one at the front door switch as a transmitter. I’m presuming the shelly app (which would be needed for the dusk control) allows one switch to trigger a different relay.