Aughhhhhh!    There was a bug that was affecting those of who had the same amounts in box 1 of some 1099R's---even though the money had come from different accounts etc. and they fixed it--- or seems like they fixed it.   Have you completely exited from the program and relaunched it to put in the updates?   You might have to call customer support for more help--if they can help.

To call TurboTax customer support

https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number

Customer support is available from 5 a.m. to 9 p.m. Pacific time

This is a copy/paste of the email they sent to me recently when they fixed this:   Maybe it will help you.

There’s an update on the TurboTax help article you’re following: "Why am I getting a 1099-R Duplicate rejection error message when my 1099-R's aren't duplicated?".

We’re happy to inform you that we’ve updated TurboTax and resolved the issue you experienced

If you’re using TurboTax Online, it’s been updated automatically. Just sign in and you can continue working.

If you’re using the TurboTax CD/Download Software, download and install the latest update. You can do this through the prompt when you launch the software or by following these instructions.

If you’re still having trouble or there’s anything else we can help you with, feel free to give us a call.

And....I am on a Mac too using Big Sur.