NinjaFirewall destroys the backend of the template “Courage”

I installed NinjaFirewall with the Courage theme and there was no issue.
Is there any error (HTTP or PHP error, a blank page), or is the layout in the backend all messed-up?

Thx for your reoly.
It looks like this German page
https://webhosting.de/wordpress-backend-designfehler-layout-zerschossen/
(blue text).

Open your browser console (CRTL + shift + j) and paste here all errors you see after the page has loaded in the “console” tab.

Did you enable some policies from the “Firewall Policies > Advanced Policies > HTTP response headers” section?

My preliminary solution: other firewall.
I will try again ninja fw with the next WP revision.
Thanks

Last days I updated WP to 5.6.2 .
Now, Ninja Firewall works good,Courage theme works good.
Problem resolved.