Am I understanding this correctly that it happens every time? Not sure if I can create a new issue... I have a similar problem of a newly created OW portal, but it doesn't happen every time. My two original linked portals work as expected most of the time, but every once in a while, it spits me out at a new portal that's always in the same spot, that I break every time.
Sure!
OW: -1513/-1514 58 -1181
N: -174 43 -139/-140
The random new one has popped up a few different orientations but is within a block either way of -1376 34 -1121
seed is -2207802877571978244
When I tested it after the first time, I went in and out every which way and side and it worked fine. The only different thing that first time was I had a splash potion of weakness on me from curing a villager. I figured I somehow confused the inner maths, but then it happened again later.