We have the same issue, on iOS 18 some Chinese characters are missing, same build works perfectly fine on iOS 17. Any solutions yet ?

The macOS bundle being flagged by security, doesn't really seem like Unity issue. I only target iOS so if I build plugin without macOS platform (ignoring the playmode warning) I will still get errors "DllNotFoundException: AppleCoreNativeMac assembly: type: member:(null)" when entering play mode...