The first portal I created worked fine. A new portal was created about 100 blocks away upon my initial return to the over-world. I then decided I didn't like the location of the first portal, and so deactivated it and destroyed it completely. I built a second portal roughly 20 blocks from the location of my first. This second portal now crashes my game every time I try to enter it. I have tried deactivating and re-lighting it, but to no avail. Interestingly, I can still access the nether through the return portal that was created after my first visit (it takes me back to the same portal that was created in the nether upon my initial visit).

Some other info about my second (malfunctioning) portal:

• It is built at Y:11
• A zombie-pigman spawned through my portal the instant it was activated
• The game consistently achieves the "nether loading screen" before crashing

Side Note: This is in a world that I created after updating to 1.16.0.57.

Thanks!