Thunderbird always opens links in Chrome even though Firefox is the default

[glitterball]

Thunderbird always open links in Google Chrome even though Firefox is set as the default browser (both in System Setting and in Firefox itself).
Both Firefox and Thunderbird are are the snap versions - I tried using the Thunderbird version from .thunderbird.net, but the problem persisted.

I have tried changing settings>>Files & Attachments>>https , but changes do not 'stick'

I have tried various changes to https in the Config Editor, but it makes no difference.

The only way that I've found to make links open in Firefox is to completely delete Google Chrome from the system.

[claydoh]

The post just before yours maybe?

https://www.kubuntuforums.net/forum/...om-thunderbird

[glitterball]

Unfortunately I couldn't use the MozillaTeam PPA version as it is older than the one I currently use, and it won't accept my profile (with nearly 20 years of emails in more than 15 accounts).

I've switched back to the snap version, but my Task Manager icon is now broken as well - no thunderbird icon when running.