When creating a custom world (officially or via mods) my skins are changed.

Changes in Skins:

When entering customizing maps (official or mods), pressing the pause button and going to the option to change characters, all the skins that I have are changed to Steve's default skin. But when I go back to the home screen my skins come back normally.

Note: It is important to mention that it is Steve's default skin before the visual update (you can tell by the texture/pixel grouping).

 

Map that was used for testing: Spellrune (available for free on the marketplace).