I have your pack and have used some of the assets in our prototype game. We are converting to UE5. However when I try to convert your meshes to nanite they no longer accept the materials. It appears its something to do with UV’s. Any advice?
Hello, please to meet you ^^
The Nanite system does not support the masked and two-sided materials at this point 
It’s sad but no-one could anticipate this thing at the time the pack was created…
We all have to wait from Epic to fix this issue i guess
Regards
PS: i found this interesting Youtube video
Nanite makes the material of the asset disappear or darken in UE5 EA
Check the comments ^^