Nether portal teleports player to the same coordinates as overworld. Reverting to 15w40b "resolves" the issue

I recently updated from 15w40b --> 15w41b

In 15w41b:
My nether portal teleports me to the same coordinates in the nether as the portal is located in the overworld., and does not create a portal in the nether in this process.

• Breaking the portal in the overworld and relighting it does not solve the issue
• Building another portal and destroying the original does not solve the issue
• Thus far I could not recreate this issue in another save

I reverted to 15w40b:
No issues with nether portals