Kenneth Anderson

The problem isn't the inventory, it's the second player in split screen having to join on a guest account - which does mean you inventory doesnt come with you, but isn't the root of the issue. As stated, fixing the issue with the guest accounts will fix everything else discussed in this thread. (Just be sure to unequip and put all items in chests while logging off a guest account, cause if they fix the issue your stuff will disappear)

So you're saying the local multiplayer is also having this issue on Xbox? Interesting.

Just so everybody knows, and in case any admin happens to look, the only issue here is while playing split screen on a Realm the 2nd player is logged in under a guest account. Fix this and all these other issues sort themselves out.

Literally every problem noted here stems from split screen realms being replaced with a guest account. The problem was fixed almost immediately on Xbox so it wasn't intentional - if they fix that all problems with inventory and account sign-in while playing on your realm should be fixed… but apparently Mojang is in no hurry to fix their most popular feature.

Split screen local works just fine but split screen in a Realm is busted on PS5 and you can only join as a guest