Cannot login - "Error: token is not valid". Why?

Hello! I just did a fresh install of Matomo, turned on 2FA, and successfully logged in and did some initial administration of the site & generated a token to login from mobile.

Suddenly, logging in from web with same (admin) credentials is giving [Error: Token is not valid]
iOS app is still able to access using the token I generated above.

What to check in this situation? Scanning the forum, looks like I am not alone in facing this issue.

Is your server well synchronized with Internet time? I know 2FA needs accurate time measurement…