Why does TTax allocate 50% of my duplex tax and insurance cost when I itemize along with 100% of the same tax and insurance costs, i.e. 150% of total tax and insurance?

[8years2do]

TTax offers option to allow TTax to allocate tax and interest to personal use and biz use but when I enter $5000 in interest, and 50% personal and 50% rental cost, TTax claims I can deduct $7500.  Is that right?

[Critter-3]

Enter ONLY the duplex  rental 1/2 in the rental section and enter the rental portion of the common expenses only in the Sch E entry section.   Do NOT try to use the "partial home rental" interview as this will mess things up as you can see.   Enter the personal portion of the common expenses in the Sch A section yourself and things will work out better.  

[8years2do]

Older (but not much older) versions of TurboTax handled that condition.  What happened in 2019?  I don't think 2018 did and the three years before that TTax couldn't handle my Casualty NOL so I had it done by an attorney.  For someone who doesn't do taxes, that subtlety can be overlooked.  I was ready to send it in.  Measure once, cut twice?

Thanks for pointing that out.