FX505DT repeating 'stuck' keys

[Sentreal]

I've had my FX505DT for a couple of years now, and it has performed reasonably well.

I currently dual-boot Fedora and Windows 11, on two different drives, and have upgraded to 16GB RAM. I did this not long after purchasing the device.

Recently, certain keys on the keyboard seem to work okay when I first turn the machine on. Then later they're patchy. So the letter 'n', for instance, will sometimes work, will sometimes not work, and then — usually after this latter occurrence — will input more than one instance of the character.

This has spread slowly throughout the keyboard and sometimes, bizarrely, affects only capital letters where I attempt to input them with the Shift key.

The problem persists across operating systems.

Has anyone else experienced something like this?