Small empty window shows up for an instant and steals my focus whenever I get a Steam notification

[Reonu]

Your system information

• Steam client version (build number or date): 1713317598
• Distribution (e.g. Ubuntu): EndeavourOS with KDE Plasma up to date as of April 21st. Running Xorg, not Wayland.
• Opted into Steam client beta?: [Yes/No] Yes, Steam Families Beta
• Have you checked for system updates?: [Yes/No] Yes
• Steam Logs: [generate by running this command in a terminal tar -zcvf ~/Desktop/steam-logs.tar.gz ~/.steam/steam/logs] Got the following error trying to run this command: tar: Removing leading `/' from member names tar (child): /home/dani/Desktop/steam-logs.tar.gz: Cannot open: No such file or directory tar (child): Error is not recoverable: exiting now /home/dani/.steam/steam/logs/ /home/dani/.steam/steam/logs/vrwebhelper_settings_desktop.txt tar: /home/dani/Desktop/steam-logs.tar.gz: Cannot write: Broken pipe tar: Child returned status 2 tar: Error is not recoverable: exiting now
• GPU: Nvidia RTX 3070

More details: Dual monitor setup. One 1440p monitor as primary on the right and one 1080p monitor as secondary on the left. Both are 144 Hz. Using 125% DPI scaling. Note that the empty window always shows up in the secondary screen (which for some reason is also where Steam puts its notifications)

Please describe your issue in as much detail as possible:

Whenever I get a Steam notification, an empty X window appears in a corner and closes itself instantly. Annoyingly, this steals the focus from whatever window I was interacting why. Especially annoying if I happened to be typing something. More specifically, the empty window seems to show up as the notification is going away, rather than when it appears.

Steps for reproducing this issue:

1. Ask a friend to spam you with lots of messages (have notifications for chat messages enabled)
2. Minimize the chat window while you're being spammed
3. Suffer through a million empty windows as the notifications go away

Here's a screenshot of the empty window. Note that the window is transparent, so I've censored what was behind it.

[kisak-valve]

Hello @Reonu, this issue is already being tracked at #10758. Closing as a duplicate.