Try taking the "native" off the dot1q line. The native vlan is untagged and I would think you want all your traffic to be tagged. nterface GigabitEthernet0/0/2.912description Management NETWORKencapsulation dot1Q 912 nativeip address 10.9.12.1 255.2...
Looks to me like your authentication has failed.
*Sep 21 16:22:57.921: IKEv2:(SESSION ID = 1,SA ID = 1):Received Packet [From 10.10.12.66:500/To 10.11.90.2:500/VRF i1:f1]Initiator SPI : 8043E2A8477F206B - Responder SPI : 1B1073A2B00CA757 Message id...