mule wont come back from nether

Put the summary of the bug you're having here
my mule would not come back from the nether after it went into the nether
What I expected to happen was...:
Describe what you thought should happen here
it would come back to my normal world
What actually happened was...:
Describe what happened here
the portal would not bring it back to the normal world
Steps to Reproduce:
1. ... make a mule go to the nether
2. ... try and make it go back to the normal world
3. ...