php only seems to work in "Apache mod_php"

hello -

ever since i upgraded from php5.4 to 5.6 and tried to clean up some previous junk, new virtual-servers seem to function strangely.

here are my steps to reproduce the issue:

1) create new virtual-server using only the DNS domain enabled? and Apache website enabled? checked

2) enter /home/marksdomaintest.com/public_html, and create a simple php phpinfo(); script.

3) test to make sure it is working properly.

4) attempt to change the default(?) Apache mod_php to either:

CGI wrapper (run as virtual server owner)

or to:

FCGId (run as virtual server owner)

5) now the tiny script just merely downloads and does not execute.

it will go back to executing normally if I [re]select Apache mod_php again.

any thoughts?

EDIT: maybe same issue as https://www.virtualmin.com/node/64638