Spongeforge can't set NPC's skin

Sponge Sponge Development
1

This code works fine on SpongeVanilla, but not SpongeForge.

e.offer(Keys.SKIN_UNIQUE_ID, UUID.fromString(customSkins.get(key)));

Is there any workarounds? There’s no errors or warnings in the console/logs.

2

Whats your spongeforge build?

3

This is my spongeforge
spongeforge-1.12.2-2825-7.1.7-RC3774.jar

4

And what sponge vanilla did you use?