If I have virtual server configured to use Automap (instead of SNAT), does the IP address used change with every session to the virtual server or will it remain the same?
That depends on how many eligible IP addresses you have. Here's how the IPs are selected:
https://support.f5.com/csp/article/K7336
Pay attention to the note:
"When there are multiple self IP addresses on the egress VLAN, the BIG-IP system alternates the addresses using a load balancing selection similar to the Least Connections load balancing method."
