. . . . I forgot and had to reset the password.

What password are you talking about? If you are talking about sync;

Resetting the sync password, or changing its e-mail will remove all data from the servers. The username and password are used to create the encryption.

This is a security feature. https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information

• I've lost my Firefox Sync account information - What to do
• I’ve forgotten, or don't have access to, my Firefox Account email address

Note: Only the data on the servers is cleared. The profile data is not changed or removed.

If you have other members of the sync, and they are working properly, you can get the data you want from them.

Note that Sync isn't designed to be used as a backup, but is merely meant to sync data between connected devices. Best is always to backup your personal data locally.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Once you reset the password of the Sync account then you can no longer use Sync to access your previous data on the Sync server as stated above. That is why it is important to remember and backup this password. A recovery key that can be used instead of a password reset is even longer and impossible to remember and thus should always be backed up.

• https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information
• https://support.mozilla.org/en-US/kb/reset-your-firefox-account-password-recovery-keys