1916537 - On scaled mixed DPI multi-screen KDE Plasma setup, event reminder dialogs are too large on the screen with the lower DPI

Status: UNCONFIRMED

(Thunderbird :: Untriaged, defect)

Description

[Nate Graham]

Attachment: Mismatched window and content sizes.png

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:129.0) Gecko/20100101 Firefox/129.0

Steps to reproduce:

0. Be using KDE Plasma as your Linux desktop environment
1. Have two screens and scale them with different scale factors. In my case, 4K@225% and 1440p@100%.
2. Have an event on a Google Calendar with reminders/notifications attached to it.
3. Set up Thunderbird to sync with this calendar, and launch Thunderbird.
4. Move focus and the cursor to the screen with the lower scale factor.
5. Wait until a reminder triggers and Thunderbird shows a dialog for it.

Actual results:

The reminder dialog appears on the un-scaled screen, and its window size is correct, but the content within it is scaled according to the scale factor of the other screen. See attached screenshot. This is 100% reproducible for me, and has been happening for years, I just got annoyed enough to report it now. :)

If I close the dialog without resizing it and moving it, when the next calendar reminder dialog appears, if it's on the scaled screen, then the dialog itself is enormous, approximately the pixel size of the inappropriately scaled content area of the prior dialog.

Expected results:

The dialog's window and content match in size.

Comment 1

[Tracey Clark]

This has been happening on my system for quite some time, on Plasma 6.1.4, with Thunderbird.
I cannot reproduce on master if Thunderbird is on the laptop display, but I can with it on the external display.

6.1.4 system
KDE Plasma Version: 6.1.4
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2
Laptop display 3840x2400@150%
External display 3440x1440@100%
x86_64

Comment 2

[Tracey Clark]

This is now affecting the Firefox profile selection window as well (v137.0)