@AMSB 

Did you completely turn off the Move 2 in the meantime? Maybe the software has to read the battery status again after a restart. 
Normally the app should show 100% after the device was fully charged. 

@Schlumpf this is a good idea, we keep it on for Alexa, but I will try and report back.

 Happy New Year!

Is the charge indicator showing that the unit is on the charger? If the unit is not sitting properly in the charging ring, the speaker will slowly discharge. Don’t be afraid to check for silly things. Last weekend I added a pair of FIVE’s to a system. The next morning I noticed that one of them was offline. On investigation I discovered that I had plugged the unit into a switched power outlet and someone had turned off the light.

The unit has been on the charger and the app shows that it’s on charge, but it’s still draining. Thanks everyone for your help, but I’m thinking there’s another issue.

Is it now below 94%?

It went down to 90%. I plugged it in using the USB-c port and it went up to 100% pretty fast so it must have to do with the base or the base ports.

I would call support and ask for a replacement. Imho something with charging via the move base is wrong.