You have several alternatives:
1-Try to add other water asset (maybe yours has a bug)
2-Show your code (Maybe we found the bug)
3-Do not add water (The most easy way)
4-Update to UE5.3 (So, you verify if it is not a engine bug)
it is the river defult water material in unreal+it was working well but after the project became bigger it crushes and i think that my trash pc is the reason where it is i5 4590 gtx 750ti 8GB Ram next week i will upgrade to ryzen 5 5600x and rx 5700xt 32GB ram is it good or i must get nvidia gpu where i heared that it’s drivers is better for 3d programs? i think the only card in this budget is rtx2060:( but rx 5700xt have more 2gb vram which is good for the future too and have much
better performance in games but i don’t know which is better for unreal