It could also a phishing attack. Verify well whether the links shown in the email, point really to the genuine Garmin's website, before entering any data there. For example if you already entered your password on a website without verifying its origin, and cannot log in now, then contact the Support.
when logging into the web site it told me I needed to reset my password.
That's highly suspicious. Are you sure it was the genuine website of Garmin, and not just its visual clone (phishing website)? Regardless, I suggest contacting the Support, and reporting it to them.
It’s definitely genuine. As soon as I changed the password the connect app is logging in with it.
Report it to the Support anyway. It still could be a phishing case, capturing your password in the process. And even if it was no phishing, if there was a request for the password change, the Support should be able to find out, why it was triggered.
