fresh install xymon shows exe contents on screen

Hello,

 
After a fresh install xymon 4.3.30 on a new server (ubuntu 20.04 ) the
website shows up.

When I use a link to a html file on the server there is no problem
(allnongreen view, main view)

 
If the link uses the cgi folders then the screen is filled with (I Think)
the contents of an excutable.

Starting with the text ELF.

 
I can't find errors in the apache2 logs and also the xymon logfiles shows
nothing to work with. 

Where should I look to fix this. 

 
I want to migrate my current hobbit configuration from a centos 7 machine to
this one

 
Thanks