Problems with OpenBSD httpd server

Hi there,
my local grav installation on a Debian machine as well as the installation on my hosters server run fine and without any trouble - I like Grav.

But now I have to install Grav onto a OpenBSD 6.7 machine with the HTTPD web server. I installed PHP and made a simple HTTPD configuration. So I was able to call static websites and also the phpinfo.

Then I installed Grav and gave it a call. The main page appeared, saying that the extensions GD, CURL and ZIP were missing. That was correct and so I installed and enabled this extensions - one after the other.
The curl and gd extensions worked properly and Grav confirmed that they were installed. But: After enabling the zip extension Grav gave me a “404 - not found”

I can monitor in the foot of my lynx browser that the call works, Grav seems to notice that all extensions are enabled and then calls the admin site - and then gave me the 404.

When I try to call gpm or grav at the command line, this failed and the answer is “env: php: No such file and directory”

Looking into my php_fpm_7.4 I see that it is compiled including zip.

Extremly crazy is, that tis 404 behaviour appears always after I enabled zip, but still remains, when I disable zip.

Any idea? Or was it a bad idea to use the OpenBSD HTTP server?