I am choosing TurboTax to do the math automatically.
Not a good idea. Especially for your specific and explicit situation. It's just to complex for the program to deal with. The program can not, does not and will not split everything correctly between SCH E and SCH A. I highly recommend you elect to do all the splits manually, and then do so.
One example of things is will not split is property insurance. Property insurance is prorated and the prorated amount is a SCH E deduction. Property insurance is not deductible at all on SCH A, as it's not an allowed deduction for the personal use part for the first 10 months, and it's not deductible at all anywhere for the period of time the entire property was your primary residence. The prorated amount is fully deductible for the period of time it was 100% rental. But as you can see, "all" amounts for insurance are pro-rated based on percentage of business use for the first ten months, and based on the percentage of time it was a full rental for 2021. The program just flat out can not handle your specific situation automatically.
