I haven’t discovered a pattern to this yet but my tablet struggles to charge, even with official charger + cable.
Charging with it completely powered off seems to randomly start the tablet through the night and then it will charge really slowly or not at all. I’ve had most success in windows by putting the tablet to sleep via power menu before charging but even that fails sometimes and I come back 6 hours later with an extra 5% charge.
Android is no different, sometimes it charges properly and sometimes it doesn’t.
So how do you charge your tablet reliably?