Your output is still showing that the SRX is sending IKEv1 and the ASA is setup for IKEv2.
You need to add the IKEv2 setup to your SRX.
set security ike gateway ike-gate-SITE-A-DH IKEv2
Your output is still showing that the SRX is sending IKEv1 and the ASA is setup for IKEv2.
You need to add the IKEv2 setup to your SRX.
set security ike gateway ike-gate-SITE-A-DH IKEv2