I assume you remember when Apple released V10.15.5 of Catalina. It basically broke both SuperDuper! (SD) and Carbon Copy Cloner (CCC). CCC did release a fix, but SD did not. I actually went back to V10.15.4, but then the issue was resolved in V10.15.6 (and is OK is V10.15.7).
That's interesting, because I've never had an issue with CCC.10.15.5 and otherwise, it's worked for me without fail.
When I say "broke", I meant that the backup/clone would not be able to boot up one's Mac. As I stated, Bombich software did release a fix, but then things were fixed overall in V10.15.6 of Catalina, and thus SuperDuper! (and Cartbon Copy Cloner) functioned like before V10.15.5 was released.
