After some time of idle, i.e. leave the computer for some time, say over night. No suspend or hibernate. Back to the computer next morning, unlock. Then Firefox appears frozen/hang, can't switch tab (clicking tab has no response, but not really frozen, sometimes responses after dozens of seconds of lag), page also has no response. Then after around half to 2 minutes, everything back to normal. During the "hang", CPU load is load, no memory stress (swapping/paging). Environment: Firefox 123.0 (64-bit), (actually it bothered me for years) Linux 6.6.15-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.6.15-2 (2024-02-04) x86_64 GNU/Linux ``` lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux trixie/sid Release: n/a Codename: trixie ``` Not related to particular Linux and/or kernel version. CPU: Intel or AMD, not related. RAM: 64GB/96GB, free memory more than enough. I will gather more detailed info later.