Nether Portal Linking (w/ minimalist example)

Perfectly aligned Nether Portals linking incorrectly which seems to be fixed by "Y" coordinate changes.

I've attached a world download (Bedrock 1.12 of course)

3 min YouTube video link illustrating the bug very concisely.

 https://www.youtube.com/watch?v=_iLKjBShaHs&feature=youtu.be