I've upgraded to 5.20 from 5.17 and I've had to modify my /boot/bin/micro.bin to activate the VGA output.
After Upgraded the board didn't reactivate the VGA, and I've to do it manually.
Maybe some warning in the changelog will be an help to those have to do such modifications.
The upgrade process copied the bin dir to bin.old.
I have to apply "sudo apt-get upgrade" twice as the first run complain about come conflicting files and abort the upgrade, the second run did the job.
I'm running legacy debian Jessie image and upgraded from 5.17 to 5.20.
Now it seem to work well.