Does it matter: took a partial 2020 RMD dist. Now get warning message:Form 5329-T Waiver of tax should not exceed the RMD shortfall. perhaps I entered something wrong?

When asked, you should have answered that you were not required to take an RMD for 2020.

You can delete the Form 5329 by clicking Tax Tools -> Tools -> Delete a form, then clicking the Delete link for this form.