You can configure: same-security-traffic permit intra-interface
As well as configuring TCP state bypass, but pls kindly be advised that it really defeats the purpose of having a firewall (FWSM) in place if you configure it to bypass the TCP state as it could have been an attack and the FWSM will not detect that because you have configured it to do so. However, this will resolve your problem.
Here is more information on TCP state bypass and how to configure it:
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...