Hi,
After investigating a bit more, we realized that Nanite Tesselation was the cause of the issue. Disabling it allows us to play our level without the mentionned hangs/tdr crashes.
For a bit of context, we use nanite tessellation on our terrain and ballast materials to simulate small rocks on the ground with displacement.
This results in tessellated geometry taking quite a bit of screenspace, but overall performances seems alright, especially since the introduction of the Fade parameters.
The only issue is with those punctual hangs, which I would guess is caused by Tessellation suddenly and briefly generating too much nanite data for whatever reasons, since lowering r.Nanite.Max* parameters seems to reduce the length of the hangs.
I don’t really have any idea how to further investigate on my own, but I’m currently bundling up a workspace to communicate to our contact at Epic, for investigations on other issues.
I will see if it is also possible to send it here or directly to you so you can use it as a reprocase on this issue if still needed by then.