From testing a bit more, it seems like this only happens when the colliding block is in a different chunk than the portal itself (which is true for the coordinates in the reproduction steps).
In other words, AFAICT the portal collision check only accounts for blocks in adjacent chunks if those chunks are already loaded. I've updated the issue title/description.
not-an-aardvark
From testing a bit more, it seems like this only happens when the colliding block is in a different chunk than the portal itself (which is true for the coordinates in the reproduction steps).
In other words, AFAICT the portal collision check only accounts for blocks in adjacent chunks if those chunks are already loaded. I've updated the issue title/description.