This is pretty much what I get - except using an iPad. Have tried moving my fan further away; tried wiping and restoring the iPad; tried removing the bluetooth cadence sensor; tried riding without phone/airpods (no music). Can’t see that its local interference. Did try switching to 5kHz wifi, but the extender gave up after 24hrs!
I have hit the occasional ride where I can go for 60mins plus without a dropout, but halloween rides with hordes of riders, two dropouts in about 10 minutes.