This happened to me as well and I may be able to help.
- First of all click on this link. It will direct you to the Facebook Business Help Center. Log into Facebook
- Scroll to the bottom of the page and click on the “Account Quality” Link
- It will direct you to the following page.
- Next click anywhere on your account shown at the bottom. You can click on your Profile Pic, The Red Highlighted “Account Restricted” Label or anywhere in that area.
- You will then be directed to the following page.
This page will show you the reason behind your account restriction at the top. And give you the solution on the right. In my case all I had to do was Enable Two Factor Authentication to resolve the issue.