Not really a question I'm just posting here for posterity. I'm also not really sure where you go to report bugs.
In my microflow I called microflow which I called "CurrentUser". This call returns a string variable. Using that name "CurrentUser" however causes the platform to retrieve something else instead of the string the microflow is supposed to return. Changing the name to anything else fixes the issue.
Here's the erroneous string it returns when named "CurrentUser":
[MendixObject:: type:Administration.Account id:[MendixIdentifier:: id=37154696925806894 objectType=Administration.Account entityID=132] state:NORMAL members:{Group=MendixObjectMember, FirstName=MendixObjectMember, WebServiceUser=MendixObjectMember, Dashboard=MendixObjectMember, System.User_Language=MendixObjectMember, System.changedBy=MendixObjectMember, System.User_TimeZone=MendixObjectMember, System.UserRoles=MendixObjectMember, EmailAddress=MendixObjectMember, SFTP.Connection_Account=MendixObjectMember, Name=MendixObjectMember, changedDate=MendixObjectMember, Active=MendixObjectMember, createdDate=MendixObjectMember, System.owner=MendixObjectMember, FullName=MendixObjectMember, LastLogin=MendixObjectMember, SocialWall.Profile_Account=MendixObjectMember, IsAnonymous=MendixObjectMember, FailedLogins=MendixObjectMember, IsLocalUser=MendixObjectMember, Blocked=MendixObjectMember, Password=MendixObjectMember}
I haven't tested on anything other than 6.10.3