I have encounter a bug twice now (in the same world and over the last 1-2 weeks) where going into a specific Nether portal has taken me to a random places very far away from my main location (and not linked to the portal on the other side). The first time it just left me stranded (about 10000 blocks away) and I have had to make my way through the Nether to get to familiar ground. The second time it did the same, but this time did create a new portal in the Nether, however returning through it deposited me somewhere extremely far in the main world. It's taken about 45 mins to walk/dig/bridge back both time.
99% of the time the portal has worked as it should - taking me back and forth from fixed locations. However, it is very challenging to be unexpectedly stranded in challenging locations.
Could you investigate for me? Not sure if anyone else has reported this?
MCPE-115933 Portal takes player to same X,Z coordinates in Nether as were in Overworld