My wife and I would like to swap Mac’s, with me getting her new M1 mini and her getting my iMac 2016, which is on Catalina. She wants to stay on it and not go to Big Sur - does not like it on her M1 mini. I tried plugging her Time Machine backup into my iMac on Catalina, but Migration Assistant does not recognize the drive, while Finder does. Could it be that Migration Assistant cannot migrate to a Mac that is on an older macOS version?
That is the case. Upgrading is a one way system as far as that goes. I’m afraid you’ll need to migrate things manually.
@RosemaryOrchard - thank you. I’m upgrading to Big Sur.