STD freezes Firefox when opening new windows

[adrp]

Describe the bug
Recently (recent weeks) STG freezes Firefox when opening new windows. When I open a new window (almost every time) the STD extension icon on the toolbar changes into a spinner and Firefox becomes unresponsive (taking 33% of the CPU). It rarely it recovers by itself and 99% of the time I have to kill the Firefox process. I tried to enable the debug mode, but because Firefox freezes I cannot save the log file.

To Reproduce
Steps to reproduce the behavior:

1. Open new window.

Expected behavior
To not freeze Firefox.

Desktop (please complete the following information):

• OS and version: Debian 12
• Firefox version: 125.03
• Simple Tab Groups version: 5.2

Additional context
I went through all of my extensions and uninstalled those that I added recently (and a couple more) to make sure nothing changed in Firefox (apart from the updates of course).