Game freezes for 1 sec each 3 secs in unreal 5.6 and 5.7

Hi! using unreal 5.3 this was not happening. Same code, nothing has changed, just upgraded to 5.6 or 5.7. Pressing wasd and looking to a heavy polygon count object eg nanite > 2M polygons, even a single one, freezes the game for 1 sec each 3 secs. No shaders are being compiled , rhi memory is not leaking)… using default pawn. Does anyone else has the same problem? Running in pie, 4090Gtx and 128 Mb ram.

Any ideas?