Nether Portal Feedback Loop

When I enter a nether portal from the nether I am stuck at the downloading terrain screen for about 10 seconds, and then when I spawn in I am immediately transported back to the nether, creating a feedback loop. Furthermore I am taking damage when I exit/enter the nether portal leading to many lost items and unfortunate deaths.

What I expected to happen was...:
I expected to be transported back into the overworld.

What actually happened was...:
I was transported to the overworld and immediately transported back to the nether, taking damage, and getting stuck in a feedback loop.

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
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