Exact same issue. Been having trouble ever since I installed Big Sur. This is one of the worst OS upgrades I’ve ever dealt with from Apple. It’s ridiculous that it’s been an issue for this long. The words apple, and quality, are no longer synonymous.

I've having the exact same problem. It happens every 2 to 7 days, but at least once a week. It started with the Big Sur OS installation. Never had a problem before upgrading to that OS. ASeems every OS Apple releases, whether on a laptop or phone is bugged to the point it shouldn't have been released. This system crasher has been here for months. It needs fixed yesterday. Sincerely question whether quality is something Apple cares about these days, much less prides itself on. panic(cpu 4 caller 0xffffff8006d64a25): userspace watchdog timeout: no successful checkins from com.apple.WindowServer in 120 seconds