You can call but the agents in the call centre will have no idea and you are never given an actual reason, you must have violated their user agreement OR acceptable use policy in some way.
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.
Advice is voluntary. Kudos / Solution appreciated.