Systray icon freezes after message/alert

Background

I'm developing PyQt applications and am using Qt's QSystemTrayIcon.showMessage function

Problem

The system tray icon chosen for the application is not restored after a message/alert has been shown. Instead the icon after a message/alert popup (for example an "i" inside a circle) continues to be the icon in the systray

Expected behaviour

After the timeout given (maybe 15 seconds) the systray icon should be restored to the one chosen for the application

(This is what happens for other desktop environments that i've used: LXDE and LXQt)

Instances of this issue

I've only seen this problem in Qt applications, not for example in the wireless network indicator in the systray

This is not just a problem in my own applications though, also the official PyQt5 examples have the same issue

System

XUbuntu 20.04 (64 bit)