Boost Unavailable! what's wrong in my facebook page?

Hello, I have a facebook page that have 500k likes. The fans are 100% real, I want to promote a post but under any post in my page I get " Boost Unavailable " Instead of " Boost " button !!!!

There are no problems in my other FB pages.

What's happened?

You probably got blocked for "fraud activity" whether you did anything or not. Did you use a voucher at any point?

No, I'm not using any voucher, I'm using my PayPal that have the same Name as my facebook account.