Comment 6 for bug 1873550

This issue does appear to be specific to using the snapd snap, since the snapd.failure unit is the service that gets triggered after the snapd service proper fails to exit gracefully.

If someone does hit this again, it would be useful to see output from

snap changes

ASAP after the slowdown happens on shutdown. The logs from Paul clearly indicate that snapd thinks it needs to do something at that moment, if it is happening frequently it's highly unlikely it's an automated refresh I think.

Also @fthx, note that on a fresh install of 20.04, the snapd snap is already included in the seed. It depends quite a bit on what was in your 19.10 (or earlier) install if you end up getting the core snap snapd service or the snapd snap snapd service.