Try going to the EXTENSIONS input area and enter a 1 for automatic extension. That will change the due date and should make things good with the world.
I am unsure of what you original question about estimate tax paid after 4/15 is referring to. Should it be entered as an amount paid with extension?
If you click on the diagnostic, it should take you to an entry point to "fix" the error. Can you post the error? Did you make entries for the dates paid on the 2019 ES payments? Is one of them after 4/15/2020?
You may have to contact support. https://proconnect.intuit.com/community/taxation/help/how-to-contact-proconnect-tax-online-for-help/...