In Java Edition 1.15, Mojang made a change to slim skins which raises their arms to match classic skin. This change has however, not been transferred to Bedrock Edition yet.

Moreover, item positions were not edited to be centered to the player's arm. This causes packs with flat items to have the item offcentered.

This is were this pack comes in. It not only fixes the 2 issues listed here but also has a compatibility mode, so you can enjoy the game with this pack without breaking most animation packs.

The arms of your skin will go from this:

To this:

Important Note

Due to content errors, the pack isn't enabled on the dressing room render. This extends to the paperdoll when in compatibility mode.

Additionally, if you're device is affected by MCPE-126660, you'll need to be in first person for the pack to apply. This is a temporary workaround until the bug is fixed.