Wondering if anyone has a work around for this annoying issue. When I use the task switcher Thunderbird shows as the generic Wayland icon, however in the task bar the icon is correct. I’m attaching an image
Well I don’t know there are several options for the task switcher settings , maybe try another option you would like, in system settings>window manager>task switcher.
I’m so stupid, when I initially add the desktop file setting to Thunderbird I applied the wrong file name which is why it didn’t work. using the correct desktop file org.mozilla.Thunderbird corrects the issue.