Error 404 page empty in restricted area

Hi there.

Currently I've finished a new web made with Grav https://medioreal.com.

In this site, I have a restricted area only for logged users. Below of this area I have several pages with inherit permissions. If you write any wrong address under this restricted area, it shows empty page instead Error 404 message.

What's happening? Is it a bug of error plugin?

You can see this if you visit, for example this address: https://medioreal.com/area-de-alumnos/xxx.

Thanks in advance

Looks like there should be a login form 🤔

But no login form should appear, since that page does not exist.
Error 404 message should appear

Could it be that login plugin somehow takes over error plugin when that non-existant page is under restricted path? Could you try changing plugin priorities?

I've tried with plugin priorities, with this code in priorities.yaml:

login:
    onPageInitialized:
        handlePage: 100

Also, I've changed the above code with others variants, such as onPageNotFound and with form and error plugins, but no results.

I think this is a some issue with the error plugin.