Massive lag spikes when Cinny notification is present

[JoeJoeTV]

Describe the bug

Whenever Cinny Desktop sends a chat notification, and it appears on the screen or in the Cinnamon notification applet, closing it, or opening the notifications list from the applet freezes the applet for a short while and as long as the notification is visible, the UI is sluggish in between. Since the Icon isn't shown, I presume, this is an issue with the icon. This may also be an issue with Cinnamon, though I have never observed this behaviour with any other application that sends notifications.

Reproduction

1. Open Cinny Desktop
2. Wait for Notification
3. Try To close the notification or interact with it

Expected behavior

No lag/sluggish UI

Platform and versions

1. OS: Linux Mint 21.2 Cinnamon
2. Cinny version: 2.2.6
3. Matrix homeserver: matrix.joejoetv.de (self-hosted)
4. Downloaded from: Flathub

Additional context

This happens both on my Desktop and Laptop, both running the same Linux Mint version. I haven't found ynthing in the Xsession logs about this.