IPSec failing when there is an F5 device in the middle

Hi Experts,

I know this was asked before but I still did not found any solution.

Scenario:

Site A(ASA)——(Internet)——(F5)—-(ASA)Site B

All ike parameters are identical.
Public IP on F5 and private IP on ASA Site B.
Public IP on ASA Site A.
Virtual server created on F5 and a route pointing to ASA Site B.
Virtual Server got all ports set for the service port.
NAT-T enables on ASAs.

ADDITIONAL INFO:
In Site B I am receiving the proposals from Site A with the original public source and destination IP.

Any other ideas? Thanks in advance!!