All work's correctly, but I can't see myself as mob in third person.

1.18.2 - Forge
Mod version - identity-2.3.0

I have this same issue with identity-2.6.0 on 1.19.2 (all of fabric 6 v0.1.5 modpack).
As soon as you change into a mob, you become invisible. Changing back does not resolve the issue.
The only resolution I've found is to quit Minecraft and relaunch.

I get this message a bunch while the Identity selection menu is open:
[21:17:20] [Render thread/WARN]: Configuration conflict: there is more than one oshi.architecture.properties file on the classpath