Whenever WordPress acts unusual or wonky -- that indicates the possibility of a plugin and/or theme conflict.
I have an article that can walk you through the troubleshooting process: How to Easily Fix a WordPress White Screen (and Troubleshoot for Conflicts)
I think you have the same problem I have solved a long time ago
First of all you need to access to your host via FTP, or file manager from your cpanel. Next you need to go to the wp-config.php file and add the following line:
Step By step: