Can’t login in – get a loop with captcha and login form

I bought the premium version and activated it but I could not log in to my site. There is a loop with the login form and captcha that keeps running and running. I enter the captcha, get the login screen, enter the login credentials, then get taken back to the captcha form. Over and over.

I had to delete the plugin from my cPanel.

I have Jetpack security (Protect) and Limit Login attempts activated so there may be some plugin incompatability going on.

Please let me know how to solve this problem or I may need to ask for a refund because I can’t use this plugin.