As shown in the wardrobe: As shown on the site (forums, etc):

1. Google Chrome Version 90.0.4430.212 (Official Build) (64-bit)
2. Windows 10, laptop
3. For some reason, the skin is not being applied to the arm though it is applied to the face/body.

I looked at your avatar base It seems like you have "Left Arm - Fresh: Light" from Rachelle's Replacement and Repair. Try going there to the left arm and choosing remove.

removed - testing

[edit] ^^;; That seemed to be it. I didn't realize I had that selected. Thank you!