This bug is similar to MCPE-50258, however I noticed it being strangely different on my pc/Minecraft windows 10 1.16. When I tried using an Alex type skin, the left leg seemed to mirror itself, instead of the right leg. To explain what I mean, here is a skin I made showing this problem. H = Head, B = Body, LA = Left Arm, RA = Right Arm, LL = Left Leg, and RL = Right Leg. The left leg seems to be mirroring itself instead of the right leg, like in MCPE-50258. This does not seem to affect the steve skin version, as it displays as intended. It does not affect the outer layer, only the interior left leg. This also only occurs when I use custom skins, not marketplace skins.