OS: Windows 11 24H2
AMD Ryzen 7 7800X3D 8-Core Processor (4.20 GHz)
64,0 GB RAM
RTX 3090
No Extension installed (removed all)
Used "Refresh Firefox"
Uninstall and re-installed firefox
Switched to developer edition
Only a single tab is just as slow as having 100 tabs open
Firefox Task Manager shows "Firefox" CPU usage jump between 10 an 90 percent even with only one tab opened.
I have no problems with other applications or browsers whatsoever.
