I see others have done a great job of confusing you even more than you were to begin with. So lets start over. For starters, you need to provide some clarity.

I live in my rental property.

Bad choice of wording on your part. If you "live in" your rental property, then it's not rental property. Period. So it's one of two things and you need to clarify which one.

1) You own a duplex where you rent out one unit and the other unit is your primary residence.

2) You own your single family home that you live in as your primary residence, but you rent out one or more rooms in your house to paying tenants.

3) You converted the rental property to your primary residence (or vice-versa) in 2019.

So which is it? If not one of the above, then explain exactly what it is please.

Why is TurboTax is deducting my property tax twice?

Because you're entering it twice most likely.

I don't see a way to change it with out entering a number that is not on my 1098

Depending on which of the three possibilities above is your specific situation, that very well may be "exactly" what you are supposed to do. But until I know the facts of your situation, it's impossible to provide you facts on the correct path you need to take here.