NO TROUBLES! Once again, flew into and out of Cozumel (this time via DFW) with no troubles on American. I want to encourage everyone to complete the Verifly app process at least 4 hours before you arrive at the airport. You'll need to have already followed instructions to provide contact information (for covid tracing - it's just giving them your email and phone numbers, which I assume they already have anyway!); then you'll do your passenger attestation ("I am who I am and all the info I'm providing is accurate and you already have it" - birth date, passport number, flight number, where you're flying to); then you say 'yes I got tested and it was negative - and my birth date, name of tester is on the test' - and upload the document. When you're done you'll get a screen that says "READY TO TRAVEL" that will have your picture (that you provided).
Guys, when the woman at the Cozumel American Airlines line asked me if I had it and I showed her mine and Roger's she acted really pleasantly surprised - I was surprised she was surprised! Meanwhile, the family in front of us was busy filling out the forms for all their kids and themselves, followed by supervising their two teen daughters moving stuff from checked bags to carryon so they wouldn't be overweight. (We watched the first process as we were behind them until a second agent came along - and watched the second process after we dropped off our bags).
It really is an easy process - just do it ahead of time and you'll be so much happier and things will go so much more smoothly. At least that has been our experience the last two trips (January and today).