Error on Availability Group Failover

I have multiple Availablity groups set up and I am having issues with just one.  I have compared all settings of it to one that is working that I can think of and they are set up the same.  When I run the command:

ALTER AVAILABILITY GROUP [AG-MyGroup] FAILOVER;

I get the following error:

Msg 15151, Level 16, State 1, Line 4
Cannot alter the availability group 'AG-MyGroup', because it does not exist or you do not have permission.

Like I said it works for the other ones, just not this one.  I have compared security and logins, properties of the AGs and the instances.  I don't see anything sticking out that would make them different. 

Any help is appreciated.