I recently installed Ubuntu 20.04 and also, on a separate machine, moved from Linux Mint 19.3 to 20, with the move from Ubuntu 18.04 to 20.04 underlying it.
I use a Canon MG5750 printer/scanner/copier, which works fine in all respects, wirelessly, with LM19.3. The printer was picked up automatically, no installation of additional drivers was necessary.
Under LM20 and also with Ubuntu 20.4 however, duplex (two-sided) printing will not work. The first sheet is drawn back into the printer as is usual in order to print on the other side, but then passed out blank, and the second page is printed on a new sheet, and so on. The printer is also picked up automatically in these new releases and printing works fine in all other respects.
I have reverted back to LM19.3 as my working set up as a result.
Printer test pages show that under LM19.3 the driver version is 1.20.2, whereas under LM20 and Ubuntu 20.4 it is version 1.27.4.
Any comments or suggestions would be welcome - but I feel that if it worked before automatically, but doesn't in the new release, there is an error somewhere in the new release.