Are there any older authenticator backups stored anywhere

No. The available context supports only a single current backup, not multiple older backup versions or restore points.

If a fresh login or a new backup overwrote the previous backup, the older backup cannot be retrieved. One Q&A answer also states that Microsoft Authenticator does not currently support multiple restoration points.

If only two accounts from today are showing, that indicates the currently available backup content. Older Authenticator backups are not described as being stored separately anywhere else in the available documentation.

• Restore a previous backup - Microsoft Q&A
• I accidentally clicked fresh login and lost my backup. I need to know whether I can retrieve my old backup ? - Microsoft Q&A
• Back up your accounts in Microsoft Authenticator