Mac mini Backup gets stuck
My Mac mini backup keeps getting stuck since I upgraded to BigSur 11.2. It gets as far as 958.6 MB of 3GB, hangs there for a long time and then 'stops' the back-up. If I check the back up logo at the top of the screen it says the last backup happened yesterday but if I enter time machine it says the back up was more recent than that, i.e. earlier today. Nothing seems consistent. There is a back-up within the time machine with the same time as the one showing on the logo but also supposedly several newer ones.
How do I get my backups to work properly?