Everyone who posts on here about being limited always says that they had broken no rules. However Paypal do not ban you for 0 reason. What would be the point? They make far more money from you using your Paypal account than interest on any held money.
PayPal does review accounts regularly, and any concerns with security, violations of the User Agreement or Acceptable Use Agreement, compliance obligations, etc., could lead to a permanent restriction. Additional information beyond what would have been provided to you in a notification and/or email would not be available due also to security concerns and due to such information being proprietary....in other words they do not give you an exact reason, I guess because it would make no difference to their decision anyway.
Advice is voluntary. Kudos / Solution appreciated.