Garmin connect sign off

Did you force the app to stop (or did you reboot the phone) before launching it again after the pw change? If not, then the app remained connected to the account, while still being alive in the background.

I did not reboot the phone, I thought it would automatically sign off the app as I requested in the process of changing password

I do not remember where in the phone app the password is needed, but possibly only in the function "Manage Garmin Account" at the bottom of  the User Profile settings, it means only on the web. It also means the phone app likely does not use the password authentication method at all, rather identifies itself with the device ID.

There is manual sign off in the app so you would have to sign in if signed off. If somebody had the app and knew your pw he/she would never be logged off. 

There is manual sign off in the app

Where is it? I couldn't find it. If you speak about the function "Manage Garmin Account", then that's just a web interface to your account on the Garmin server.

Sign off is in the "settings" menu. It shows your app version etc. 

Ah, yes, you are right, have overseen it. In that case it looks like a rather important security problem. You should report it to Garmin: https://www.garmin.com/en-US/legal/security

Yeah, I reported the issue.

It seems that this issue has been fixed. App is now signed off when password is changed. Thank u Garmin.