GPU usage drop to 0% every couple of seconds, leading to stutter / micro freeze

Hi,

I did not see any thread about that so...
Is this problem known by devs ? Every time I play for hours, this stuttering problem will happen eventually.

I currently have a save file with a 7+ hours gameplay with 10 AI. Most of them are defeated.
Problem is, every couple of seconds, I have a micro-freeze. It is really annoying. My fleet is not moving at all. I don't have any of my planet under enemy fire. The CPU and GPU Usage are around 20-25% (yeah, the computer is litterally sleeping). But every couple of seconds, it will drop for less than a second to 0 FPS...

So this seems to be related to some background task ingame... Or maybe because of a huge AI fight somewhere (I can't see it). Maybe it drops every time a AI ship is going down or use some special ability... I don't know.

But the odd part is, every time this happens, I can see the GPU going down to 0% usage on Rivatuner. Then it goes back to normal. I never saw something like this.

This is not a lack of performance issue, I have a 13600k and a 4070Ti with 64Gb DDR5.
Also not something related to auto-save.

Any help ?

Thanks !