UE5.3 / UE5.4 - HickUps - Ray Tracing Issue

Hey Folks,

Tech Specs:
i9-7900X
RTX 4090 / 24GB
64 GB RAM
Studio Driver 552.22
Windows 10

Nvidia Control Panel
MFAA: off
Power Management: Prefer Maximum

As you see in the video after rendering HRSSs (native blueprint / different plugin) we are getting Hiccups in reflection every time after nearly 30 min. .

Turned off Lumen GI / Ref. : Same Issue
Switching from Hardware to Software Raytracing, even in DX11: Same Issue
Turned off Async Compute of Probes, Dumping Raytracing: Same Issue
Switched to different upscalers / different Anti-Aliasing Methods: Same Issue

Went through all documentations.
Traced the the whole process without seeing any weird behaving process.

All Threads in case of timings seems also fine.

Just turning off all Ray Tracing Effects eliminated the issue.
But that can“t be the solution.

Anybody encountered this issue or know what is causing it?

ADD:
Same Issue appears with older Nvidia Driver and on different GPU and Windows 11!

Cheers

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