Custom Skin Swapage

Me and a Friend were playing in our family's private server, which was set up on a desktop. I was wearing my custom skin  and so was my friend. (Note these were skins made via a skin maker app on a mobile device that we simply saved to our drive.) When we came in render distance of each other and noticed he was wearing mine, and I was wearing his. In the pause screen and skin selector, it still said we had our own skins on. Also, I noticed that when I put on the skin I made in the new skin creator that was recently added, my friend could then freely select his own skin after applying a skin he made in the skin creator. But when I tried to put back on my original skin,(Made in the app, not the game) it reverted his custom skin (Also made on the app) to the one I just applied. I'm not totally sure why this is happening. This also isn't because of the specific app we used, for my siblings use a different app than mine, and they yield to the same problem. This bug was found in Bedrock windows 10, 1.13.1 Thank you