User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:101.0) Gecko/20100101 Firefox/101.0

Steps to reproduce:

Activated the Layout: Vertical
Navigated through my messages/emails

Actual results:

When I move through my messages, the "Message Pane" size and "Emails List" is re-sized horizontally.

This is annoying, because it seems Thunderbird is giving an UI error.

Expected results:

As in previous Thunderbird versions, the "Message Pane" size and "Emails List", horizontal size should remain constant.

urbanofreitas
I see this when the message subject wraps in the message header of the message reader pane.
Does that describe your problem?
And this doesn't happen in version 91?

Or perhaps it only depends on subject length, not wrapping specifically?

I had the probably the same issue, after migrating my 91 profile to 102 Beta.

The described behaviour was fixed, after clicking once on a column header in thread pane.

(In reply to Alex Ihrig [:Thunderbird_Mail_DE] from comment #4)

The described behaviour was fixed, after clicking once on a column header in thread pane.

I agree with that finding.

It was very confusing for now though and should be fixed as many "simple" users will complain about it I think.

Reporter do you still experience this issue when using the latest update?

Resolved per whiteboard