Cross network routing issue, specifically for ports 80 and 22

Running into a problem that I think is a simple solution that I'm just missing.

This concerns two networks, network A is 1.1.1.x, network B is 2.2.2.x.

I have a computer (1) on network B, that is trying to communicate to another machine (2) that has adaptors for both networks A and B. This is routed through our router which is also on both A and B. The router has its iptables configured to accept and forward all requests to the destination computer on both networks.

I can ping (by name and IP) from computer 1 to 2 on both of computer 2's addresses/names (on networks A/B). However, I cannot ssh, or access its webpage (ports 22 and 80) when trying to go from computer 1 to 2, on network B to A. Both services work when going from computer 1 to 2 on network B to B.

Since I know thats mildly confusing wording, example:

user@computer1_netB ssh user@computer2_netB = success

user@computer1_netB ssh user@computer2_netA = fail (kex error)

user@computer1_netB ping computer2_netB = success

user@computer1_netB ping computer2_netA = success

Pings work with both DNS and IP.

Any help on where to look would be awesome, thanks!