Viewport becomes unusable after moving cursor

In my project I created a spline-based PCG using data assets, because the scene consists of a number of islands, some close to each other, some further away from any other. I instantiated this PCG a number of times, covering either a single (small) island, or some adjacent islands together… (I could use a PCG volume but I wanted to have control over the settings per instance).
All objects spawned in the PCG have nanite enabled.

Now, when I move the cursor over the project, it can happen that the image on screen suddenly blurs and is filled with large planes, all details are gone.

It seems to happen if the content of the viewport changes fast when moving the cursor but also when I run a cinematic sequence and the scene changes fast, but I got it too when trying to move an object slowly.

I can save everything, and after reopening the viewport returns to normal.

UPDATE
As it turns out, the cause seems to be related to loaded and shown spline-based PCG’s. If I hide all of them, can do everything, also when I clear them. If I enable just a number of them, it seems to be fine too.

UPDATE
This is what a top-view in wireframe looks like normally:


and this when viewport went bazurk:

On occasion, I noted that assets near the cursor turn up in the wire frame, extended in size and rotated, not distorted.

This area has landscape material set to nanite, and looking on a spline- and dataset based PCG, but the PCG is not generated. It goes wrong if I zoom in too fast in persprective/lit mode. Unrael becomes very sluggy. Re-opening the level solves the issue - most of the time

I am now using the latest Nvidia Studio driver, can that be the problem?

The problem is also in 5.5.1. Here I have 16 PCG volumes, 530 x 530 in x/y scale, 12 using the same PCG graph, and 4 another (derived) one, to create decoration onto the landscape. I placed a number of cameras to have the ability to make screenshots in different lighting conditions showing exactly the same scene. All assets I use are nanite enabled (and set to use nanite).
Moving the viewport is no problem, as long as I don’t go to fast, as described earlier.
I set up a second viewport on another monitor,
and set that to cinematic view, and select one of the camera’s - then this happens:


Video is RTX4090 (ASUS TUF), driver is latest:

Global settings:

System video settings:

Hey there @WillemGr! It’s looking like there’s mesh distortion going on. This is reminiscent of a bug that occurred when scraping some scene limitations back in 4.27. Are you receiving any errors in the console while the occurs? It looks a bit like certain PCG elements could be the cause.