Why is turbotax allocating both my federal AND state estimated taxes to my state (and fed. to fed. taxes)? I am in Virginia.

Have you enter your payments on different screens? In TurboTax, there is a screen for federal estimated taxes paid and another for state estimated taxes paid. 

To verify, you can follow these steps: 

1. Open your tax return.
2. Search for estimated tax payments with the magnifying glass tool on the top of the page. 
3. Click on the Jump to estimated tax payments link at the top of the search results.
4. Click on Start/Revisit next to Federal estimated taxes for 2020. 
5. Verify amounts.
6. Click on Start/Revisit next to State estimated taxes for 2020.
7. Verify amounts. 
8. Follow the on-screen instructions.