The same thing is happening for me as well. It's on Realms in 1.16 and after a few times the gateway stopped working and teleported us below the main island (causing us to fall into the void and die). This is extremely annoying and I hope it gets resolved. We also respawned and killed the Ender dragon a 2nd time, but that just created a new portal that teleported us somewhere else; the first portal still didn't work.
We now set up a command block to teleport us to the gateway location as a workaround. But it still sucks and is incredibly bad game experience.
The same thing is happening for me as well. It's on Realms in 1.16 and after a few times the gateway stopped working and teleported us below the main island (causing us to fall into the void and die). This is extremely annoying and I hope it gets resolved. We also respawned and killed the Ender dragon a 2nd time, but that just created a new portal that teleported us somewhere else; the first portal still didn't work.
We now set up a command block to teleport us to the gateway location as a workaround. But it still sucks and is incredibly bad game experience.