Since the 5.x kernel based releases many users have been reporting system hangs every few days once the i915 module is loaded.
With reports from a few users detailed in the thread below we have worked out that the issue is caused by the i915 module and is a persistent issue with both the 6.9.x release and 6.10 release candidates.
The system does not need to be actively transcoding for the hang to occur. 6.8.3 does not have this issue and is not hardware related. Unloading the i915 module stops the hangs. Hangs are still present in 6.10.0RC2. I can provide a list of similar reports if required.