Initial Overworld portal at 254, 10, 167
Portal in Nether at 30, 10, 36
Multiple portals appeared through the course of exiting the nether, ranging within 10 blocks of each other (X=250-260) (Z=280-290) at Y-64, and Y-30
Final Portal exit to Overworld 251, 64, 290
No new portals have formed through continuous travel, however, return to the overworld is through the initial portal about 5% of the time.
If it were working as intended, I shouldn't have that 5% chance to appear at the Y=10 Overworld portal.
My portals have since stabilized, but I'm stuck with two overworld portals to the single one in the nether. Will destroy one later to see what happens. Have so far had 7 separate overworld portals generate due to the bug.
Attached is a picture of 4 of the portals generated by the game. 3 more spawned around Y-30, which I already removed. The sole player built portal is at Y-10, about 130 (Z) blocks away.
I have never encountered this issue in any previous version of the game.