I created a skin on Windows 10 PC version. The next day I played Minecraft on my phone (Samsung Galaxy Note 10+) and the skins loaded as Steve and Alex. Both versions are linked to the same account. I decided to see if I still had the skins on my PC and they were not there either. 

The two Steve skins in the screenshot were custom skins made using the character creator on my PC version.

Syncing skins was not an issue before the most recent update.