Thanks a bunch. That resolved it. I am using Windows not Mac but you got me to the right place. My problem did not involve multiple lenders or 1098s or anything complicated, just one loan well below max allowed, one lender, one 1098. All my mortgage interest was deductible but TT was only giving me $10,240 vice $18,800. Big difference. But after I did the manual entries and TT corrected the error in deductions it could not even add my 4 deductions correctly. The 4 came to $30,326 and the total shown was $30,626. But I am not going to try and fix that.
As an aside I have been using TT since 2007 and until this year was very satisfied. This year has been terrible and TT is a joke as far as I'm concerned and it is unlikely I will ever use it again. I have made 8 calls to support and spent at least 10 hours on the phone and accomplished very little. The techs have been by and large terrible with two offering absolutely zero in effort or suggestions for fixes. It's gee, duh I don't know. I ended up solving most issues myself. Issues included failure to save after doing my input. When I reopened all data was gone. I needed to check some 2019 data and I could not open 2019 TT (known problem all over net). TT insisted Standard Deduction was best option which was ridiculous. Then every time I opened TT it wanted to update but failed. TT had me doing things like making command line entries to services etc. blaming MS (which admittedly is often a problem). Of course my computer was blamed as was my virus software. Been down that road before. I spent 23 years doing testing, documentation and scripting for a logistics software and consulting company so I know just a little. Then when update failed I could not even open TT. Ended up doing an uninstall and reinstall. After that a tech did get my deduction changed from Standard but with the incorrect amount until now.
