Issue: Various keys on keyboard do not work when unplugged. Non-functional keys vary with each incident but are scattered across the keyboard (letters, numbers, symbols, ctrl/space/shift/enter) and not clustered. It is probably not an issue with the membrane or electrical connection as the keyboard works perfectly fine when plugged in to the 65W power supply. After leaving the laptop unplugged for a while, it takes about 15min in the power supply to restore full keyboard functionality.
Attempted fixes: When I charge the laptop with a 20W power bank, the keys are unresponsive too. Have tried uninstalling and reinstalling the keyboard drivers but to no avail. The on-screen keyboard works just fine regardless of whether the laptop is plugged in.
Any suggestions on what the issue may be and how to fix it? Thanks!