Non-blocking pop-up never appears centered or remembers where it was

[thoraxe]

Describe the bug
When a non-blocking pop-up appears, it is always at the top-left of the screen, never centered.

To Reproduce
Steps to reproduce the behavior:

1. Configure for non-blocking pop-ups
2. wait for a pop-up

It will always appear at the top left.

Expected behavior
Pop-ups should be centered

Linux (please complete the following information in case you encountered the bug on Linux):

• Distribution: Fedora
• Distribution Version: 31
• Desktop Environment: Gnome 3.34
• Workrave Version: workrave-1.10.20-6.fc31.x86_64

[rcaelers]

Do you know if you are using Wayland?

[thoraxe]

Yes pretty sure Fedora 31 has Wayland enabled.

[rcaelers]

I am now opening non-blocking break windows as modal. This should center them when running Mutter (gnome). I doubt this can be solved in general when running Wayland. Wayland does not support absolute positioning of top-level windows.