>you'll notice in my screens below that under setup my subset is 255.255.255.0, yet in the status it's 255.255.252.0 ANYONE
I think I can answer that bit at least. The subnet mask value is sort of like a filter. The DHCP server of your internet provider (the thing your router is talking to, in terms of getting its external IP address) is configuring your router with that mask. A value of:
..allows for four subnet IP's to be issued. Each number (255) represents a cascading subnet filter in binary, i.e. that number is really seen as:
So you can see two '0's on the end of the 3rd grouping, which means '11' (or up to four in decimal) can be allowed through in that part of the subnet (up to 1024 individual IP's)
Unfortunately, that's not much to do with why the game isn't working. Your internal sub-net mask of 255.255.255.0 is fine
If you try something like a port scanner, no ports on the PC are exposed even though it's in the DMZ?https://www.grc.com/x/ne.dll?bh0bkyd2
Maybe try 'all service ports' or the user specified for SBPro?