I have a Nether portal right over a End portal. When going from the Nether to the Overworld and quickly (within 1-3 seconds) going through The End portal, it's not possible to interact with certain blocks (have tested chests, ender chests and crafting benches). By interacting, what I mean is opening the chests or getting access to the crafting table GUI. The issue doesn't carry over to the overworld. The issue is fixed after disconnecting and rejoining the Realm server.
Edit; rotating maps and other items in Item Frames is not affected by this.
Moved to the REALMS project.