Flow Designer - If Action comparison of reference fields not working

[Jeff77]

I have a (IMO) fairly simple If action comparison that doesn't seem to be working.  It is basically checking to see if a catalog variable is not empty, and if it is unequal to another catalog variable.  The catalog variables are both reference fields to sys_user table. 

The logic is essentially checking to see if the person that submitted a request is the budget manager of their department.  If the submitter is not the budget manager, then it branches one way, where the approval step is assigned to the budget manager, however if the submitter is the budget manager it branches another way to a central payroll team for review/approval.   Below is the If action condition set..

But it does not seem to work.  Below is a screenshot of a submission from a budget manager that somehow evaluated to true.  

Hard to see but if you expand you can see the compared values (text copied to below): 

fbf429473b5a6e1027bff2c964e45ae4ISNOTEMPTY^fbf429473b5a6e1027bff2c964e45ae4!=fbf429473b5a6e1027bff2c964e45ae4 

So I guess my question is, can one not compare 2 reference fields of the same table in an If action, or is this a bug? 
Edit: Forgot to mention, we are on Yokohama.  This has occurred in our prod instance (Patch4b) and non-prod (patch7 hotfix2)

[M Iftikhar]

Hi @Jeff77,

Please check you don't have any extra space after the data pill, because even an extra space can cause the condition to evaluate true.

If my response helped, please mark it as the accepted solution so others can benefit as well.

[nityabans27]

Hi @Jeff77,

Flow Designer can’t reliably compare two reference-type catalog variables directly — it sometimes treats them as text, not sys_id, so your “If” condition gives wrong results.

Fix:
Use a Script step (or a Record Lookup) to compare the two users by their sys_id, then branch on that boolean result.
This is a known Yokohama bug, seen even in Patch 7 HF2.