So no housing deduction for Sch C income, but itemize deduction can be taken on Sch A without reduction of the excluded foreign income. All of $31k can be taken as itemized deduction. Is that correct ?

The software took the QBI deduction. A foreign business is not allowed to take the QBI.

How do I stop the QBI deduction within the software ?

You are a very knowledgeable person and an asset to this community.