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 ^^