If you ask me, Form 1040X is messed up in this area.
You have to report in the Explanation Part iii that you are changing your exemption status.
The ONLY way to file an amended return is to print, sign and mail a Form 1040X. If you did anything else you did not amend your return. If you just went into the return and changed that one answer, it did not transmit to the IRS. If you need to amend you have to do it correctly.
How do I amend my 2019 TurboTax Online return?
A 1040X cannot be e-filed. It must be printed and mailed. It will take about 4 months for the IRS to process an amended return. It is a good idea to use a mailing service that will track it, like UPS or certified mail, so you will know it was received.
Wait about 3 weeks from mailing and you can check the status of your amended return:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
https://ttlc.intuit.com/questions/1908543-do-i-need-to-amend
Note: It normally takes about 16 weeks for the IRS to process an amended return. At present, it is taking much longer. An amended return you mail in now may not even be processed by the end of 2020, so do not expect quick results for an amended return.