Interference from the charger possibly. I've had this before with some no-name cheapo thing, a phone's touch-screen became inoperable when plugged into it. Suggest you try another charger, either phone manufacturer original or a good quality third-party one.
Some Shenzhen market cheapo USB chargers are just not screened and filtered at all and can put out loads of interference.
BTW
@W7LPN that sounds like a radio ham callsign?