In my realm, after the update, I have an issue with Nether Portal Linking. 

1) I have created a portal at my home base. It links me into the Nether. 

2) When I go to the nether and return it randomly either returns me to my original location or it creates another portal about 70 blocks away and lands me there even though my original portal is there and unbroken. 

3) The Portal has never been moved after initial creation. There are no more portals within 1000 blocks.