The problem with styles when administering the frontend

[AnSit]

GJC Web Design, I am very grateful for your help and advice! And to all who participated in the topic!
I turned in support of hosting. And indeed they found the cause of this problem! It was that by default, they use this technology to protect the backend from attacks: nginx brute force protection.
Oddly enough, it blocked the normal loading of scripts and styles.
Unfortunately, the support does not know how to solve this problem and had to disable this protection altogether.

Can anyone know or learn how to combine this security technology and the smooth functioning of the VM in the frontend - please be sure to let us know. I will be very grateful to you!

[diri]

Possibilities depend very much on what you are able to modify at Nginx' settings.

Starts with security headers, rate limit, ...

Be ensured:
It will take some hours to get some relative fine grained and working setup. 

[AnSit]

So do you think it can still be customized? The hosting support team said that you can't leave the protection and solve the problem with the normal loading of styles and scripts.

I would try to configure something myself, but these settings are most likely available only to the hosting support team.

If someone gave specific instructions on what to turn on or off, then I would pass this information to support.

[GJC Web Design]

For a start u need to know what is the rule in their "protection" that is blocking the delivery

[AnSit]

If they told me what settings they made there. They said that you cannot configure protection so that the page works normally. That's all.

What else can I advise them? Himself without understanding this issue.

[GJC Web Design]

simplest is change hosts .. this has never been reported before afaik

[diri]

I can only recommend a change of hoster as well. They don't look capable to handle Nginx.

But, be carefull with change. Other hosters might have other drawbacks.

In Germany I have a customer with not really cheap hosting at Ionos (1und1). They run Apache, customer can modify some settings with .htaccess but:
To get a security grade of A+ I had to modify  some things with PHP. Without this site had grade C.

Problem there:
Session limit is 16, PHP is running in cgi mode. Too many extra open handles (many parallel running tasks) - session limit reached. Eg backend of Piwik with default settings for one site in dashboard is disturbed for this. I must look for a reliable alternative for them as well.

edit:
Ionos (1und1) belongs to United Internet. Other lables are gmx, web.de, strato, ...

[AnSit]

Got it! Thank you all for these tips and details!