My battery reporting is stuck at at 80% on the app and the speaker?

So I have recently had a Megaboom 3 replaced under warrantee because I was getting an issue with it being stuck on 80% charge. On my new replacement it stays stuck on 40% or 80% (normally stuck on 80%) it never drops to 75% as an example.

I use both the app and the speaker to check the charge level. I have tried to reset using the power and volume down button. I have also tried the following:

"Volume Up and Down and the Bluetooth button at the same time WHILE the speaker was plugged in with the Volume Down button"

I have tried using the power up charging doc, and a cable. This is really strange because its the exact same with 2 different Megaboom 3, I swear it was not behaving like that before. Am I going insane?

Has anyone else experienced these issues.