I own 50% of a rental property when i put in 100% ownership Turbo tax drops my tax liability than when i imput 50 % ownership. it was working fine but now it is scaring me.

if you entered 100% of revenue, expenses and cost of assets then Turbotax correctly assumed that with 100% ownership entered it was all yours.  50% ownership is needed so it reports only your 1/2.  however, if you entered 50% of the revenue, expenses and assets then you need to enter 100% ownership because it's all yours