Time Machine restored Catalina rather than Big Sur
I made a Time Machine backup to a hard drive using the latest Big Sur version (11.5.1). I've just bought a 13-inch 2020 Macbook Pro (not M1) and to my horror, restoring this backup did so with Catalina 10.15.5!
It seems that my files are present (thank goodness) - including those just before the backup. Strangely, the latest version of Xcode is also present - but refuses to run since the MacOS version is too old!
I'm really struggling to find anything else on the internet addressing this problem - and would like to know what is going on. I hope that nothing else has gone wrong. Should I manually now update this to Big Sur (again)? I don't want to corrupt my Time Machine Backup.
Many, many thanks.