After having fiddled around and finally fixed my WebApps with Chromium Snap on Ubuntu 20.04, today I discovered that all my WebApps were missing from the dock and no longer available when searching for them.
The issue is related to the Snap package and the way the WebApp shortcuts are created.
When looking at the .desktop files in
~/.local/share/applications, you'll notice the Chromium binary is called for that specific Snap version for which it was created:
Exec=/snap/chromium/1123/usr/lib/chromium-browser/chrome --profile-directory=Default --app-id=<yourappid>
So in the example above, version 1123 is called. Now this works fine, until a new Chromium Snap version is released. This new version, i.e. 1143, is then installed in a new dir:
Now as soon as the old version (1123) gets automatically purged, all the .desktop files break.