Dear community, I'm encountering the following problem: While the lid of my Lenovo P1 with Debian OS and XFCE w/m is closed, Firefox 77 uses one core @ 100% constantly. Using profiler.firefox.com didn't show any unusual activity at all. Other tools like about:performance don't help since the lid is closed while it happens. As soon as I open the notebook, CPU usage drops back to normal levels instantly. Any ideas how to debug or where to look for? Best Markus