IPSEC SA

Got a strange one here, a bit out of my depth if I am honest.

I have a network that is unable to start an SA. The phase 1 tunnel is up but I can't get the phase 2 tunnel up. Other networks that are using the same phase 1 tunnel are working fine. I thought sending traffic to the network would bring up the tunnel but it hasn't done anything.

when i run

show crypto ipsec sa it doesn't actually show the phase 2 connection for these 2 networks at all. Any ideas on how I can further troubleshoot or force the phase 2 connection?

Sorry if I am not making much sense here but as I said I am a bit out of my depth to be honest. (Or at least I feel it.) I'm learning though!