@MojangSupport Been having issues with lag in the nether, in my Xbox One Bedrock world. Just seen the reason: ghasts passing through lava streams. For some reason the game really struggles with it, causing lag spikes that can last several seconds & seriously impact play.

Can you duplicate this but link your Xbox One to a hardwire connection to see if the same thing happens? If it does happen, I'm gonna have you bug report the issue. ^TK

If by hardwire you mean ethernet cable, had that while house-sitting for my brother, and was still getting the lag. For reference, I have a fibre connection, so line speed isn't an issue. Looked into bug reporting, but confused by all the different logins apparently needed.

Also, I'm now having a new issue. Twice the game has frozen while loading the overworld after leaving the nether. Just stops on the load screen. Closing and restarting drops me, literally, into the overworld.