I thought so too. But it also happens when i log into a map form the marketplace.
Their making a fix for it
Are you logged into Minecraft on another device? If so it can be the case that the skin is on the other device.
Are you in Peacfull?
I had the same issue on my PC. We were a group of friends trying to play. But keep trying and you'll eventually get it. That's how it worked for us anyways.
Your welcome!
You could report this to Mineplex theirsleves if you wish
Here's the link: https://www.mineplex.com/bugs/
@[Mojang] Mega_Spud (Jay Wells) Thanks! Servers now work and I thank you on fixing it!