I am running a program that gets blocked by sys-firewall. I switched my qube to connect to sys-net and was able to run it just fine so I determined I need to open a port in my sys-firewall for it to function while still using sys-firewall as netVM.
You have not said if the program needs open ports inbound or outbound.
By default qubes are allowed full access outbound,and no ports are open
for inbound traffic.
There should be no difference between attaching to sys-net and
sys-firewall.
What is the program?
What ports do you need open ,inbound and outbound?