Hope you are doing well and sorry for the trouble. As mentioned you have updated the plan and still get the message of "max 10 recipients"
I have checked the Adobe Account with the email you are using on this community and traced the Adobe sign for small business - Teams account. Please logout out of the application and relogin using the company profile and enter your Adobe ID/Email followed by the password and see if that works for you. For more information please check the help page https://helpx.adobe.com/enterprise/kb/enterprise-id-faq.html
Let us know if you experience any trouble and need more help.