Up until 2020, Turbotax calculated the depreciation on my rental property. For 2020, none was calculated. What did I do wrong in entering the data?

This may be a known issue. Please see this TurboTax Help page and sign up to be notified when it has been addressed.

Be careful.  The fix that TurboTax has published is not really a FIX. When following the instructions for reentering the missing rental property asset lines & re-calculating the accumulated depreciation from 2019, I found a glitch. The program is not calculating the correct depreciation for current year. (or the correct accumulated depreciation) . You can override the accumulated depreciation field, but then it spits out the current depreciation expense. Which is not editable. It does not seem to see the error in the calculation & the Federal review says all calculations are correct. But they are not. Off by thousands on both properties! No one at turbo tax able to help me yet with this. Have escalated to tech review after spending hours in Tax chats with their "experts".  Basic math shows it is calculating much too low depreciation expense for the main assets.  Not even close to what it calculated last year. Good luck.