After updating to MacOS Catalina MAMP doesn’t work anymore with root on a network mount

I have a network mount on /var/www (original on /Volumes/internet, connected to afp://nasbox/). This is the document root for my MAMP server (5.5). After upgrading to MacOS Catalina I get the following error:

[Wed Oct 09 03:56:05 2019] [error] [client 127.0.0.1] (1)Operation not
permitted: Can't open directory for index: /Volumes/internet/

I can connect to the network folder, I can see it's content if I check with a terminal, but MAMP doesn't seem to be able to read from it after the update. How can I make things work again?

*EDIT: I changed the DocumentRoot to a 'real' local folder (/Applications/MAMP/htdocs) and everything seems to be running as expected, which leads me to belief the mapping to the NAS is the problem. ls -l showed me I had all permissions on this drive (drwxrwxrwx)