Given an IPSec VPN remote access scenario, Why doesn't a server in the corporate site send replies to the remote access VPN user?

please check gre protocol does it allow by ASP

This can be related to many issues:

1-check NAT exempt configuration.

2- if splite tunnel is configured is the server IP in the splite tunnel configuration.

3-server or any layer three devices in the path (between the fire LAN interface and the server) should know a route the VPN clients pool

you can verify this simply using capture on the ASA LAN interface

4-access-group applied on the LAN interface or devices in the path.

5-Check ASP captures on the ASA during the test, is there any drops related to traffic between VPN client IP and server IP.

hope this helps.

Best regards,

Rami Haddad

CCIE security #35629