I have several users on xwiki.org in order to test Playground behavior, version 8.2.1
I've noticed problems when switching my users.
For example, I manage to have 3 users logged in the same time:
- evalica on main wiki
- chocolade on playground
- risherry on snippets
- evalica is shared on main wiki, extensions, playground
- risherry is shared on commons, contrib, design, dev, enterprise, manager, platform, playgroundtemplate, rendering, snippets and test.
- with the mention that on playground I managed to log-out and log-in with chocolade user.
I cannot reproduce locally on 8.3-M2.