When enabling (some) resource packs that add on-screen non-interactable in-game UI, like a compass or a force coords resource pack, all character skins show as steve. This may also affect resource packs that affect/change/add in-game character animations. I will link some affected resource packs below:

https://mcpedl.com/direction-hud-pack/

https://mcpedl.com/fps-counter-pack/