The cape does not apply to custom skins and it choosing a regular skin the cape will be in the wrong side of the torso.
Comments 2
Cleaning up old tickets: This ticket had been set to 'Awaiting Response', but has not received a response from the reporter (~3 months+) so is being closed as Incomplete. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines which includes steps to reproduce the problem.
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The issue of capes not being appplied to custom skins is being tracked at MCPE-53513.
For the other issue, what do you mean by a "regular skin"? Where did you get this skin from? If you're able to provide a screenshot, that would be helpful.