What to do when Time Machine incorrectly says your Mac is on battery

Macworld
Automated Time Machine backups should be a “set it and forget it” strategy. Once enabled, macOS warns you only when something goes wrong. No alerts, and–almost always–the backups have continued apace. (macOS automatically runs verification tests on Time Machine volumes, or you can perform one manually.)A Macworld reader started to receive this message on their laptop Mac and needed help diagnosing it:
No Backups for X DaysThe most recent backup did not compl