One of the most common reasons for that is when there is an invoice overdue. When a payment — for whatever reason — can’t be processed, the system will temporarily downgrade the account.
To solve this problem, you need to add another card on Subscription Settings, switch the payment method, or contact firstname.lastname@example.org if you need a manual attempt to your current payment method.
Once the overdue invoice is paid, the PRO account will automatically reactivate, and all the PRO features will be available.
If you are sure your payments are up to date and the system still treats you as a free user, you may want to check your limits. If you still think there is anything wrong, please contact us at email@example.com.