UE5 Foliage flicker speedtree

Im using Speedtree indie but after exporting any tree it doesnt matter if its my own or sample tree and importing it to Unreal engine 5.4/5.5 which is lastest version the leafs flicker and its kinda annoying i will attach video for you to see but i couldnt figure this issue i exported tree for Unreal Engine as ST9 file but also as legacy ST file and both have this problem leaf cards flicker for some reason and it seems its from the mesh because it does even if i put to the leafs some random material. I tried same file in older version UE4.27 and there it was ok.

Nanite is also disabled by default so its not from that.

Anyone experienced this problem? i couldnt figure this out for couple days alraedy

thanks