Bug when entering real estate commission expense

I am using the online turbotax premium.  For my rental property (Schedule E), when I add the line item and enter the expense amount for real-estate commission, the system then zero's out most other expense line items that I entered (e.g. interest).   If I go back and delete the real-estate commission expense line, then the other lines re-appear. 

 

I have done this a number of times, cleared my cache and browser history, and logged out and logged back in.  The issue continues to occur.  Is this just a user interface defect, meaning all of the expenses would still appropriately calculate and appear on the schedule E?  Or is this a true bug?