If you use Cloudflare, please check this :
A general tip for CloudFlare users: it is recommended to set a rule on the wp-admin part of your website and disable caching, as it may interfere with various plugins. One frequent case is the WordPress content editor not displaying properly or redirects happening when they shouldn’t.
This is generally recommended to be set, not only when you’re using WPEP.
1. Login to www.cloudflare.com
2. Click on the website you want to remove caching from the wp-admin
3. Click on the Page Rules tab
4. Click Create Page Rule
5. Input your website name without http:// or www.
6. Add the rules as in the screenshot below:
I hope this short guide helps you in configuring Cloudflare to not create problems or random issues in the future.