This seems to be the same or a very similar issue as posted here: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/5455 I will be posting further updates there.
- Bug#1076708: short screen blackouts on intel iri... Piotr Morgwai Kotarbinski
- Bug#1076708: short screen blackouts on inte... Piotr Morgwai Kotarbinski
- Bug#1076708: short screen blackouts on ... Piotr Morgwai Kotarbinski