Going back through nether portal causes sufficcation

When I was playing on my bedrock edition realm, I went to the nether and linked the portals. When I went back to the overworld I took about a heart of suffocation damage. I also used a second account to see what is actually happening during the loading screen but when I looked I was just standing in the portal, taking damage.

 

https://www.xbox.com/play/media/DD5TTBHNNG