Couldn't try it on the lab but it must work.
You can also check the logs for trouble shooting
when HTTP_REQUEST {
set SessionId [HTTP::cookie ASP.NET_SessionId]
log local0. "[IP::client_addr]:[TCP::client_port]: Request SessionId is: $SessionId"
if { $SessionId != "" } { persist uie $SessionId 28800 }
pool po-server-https
}
when HTTP_RESPONSE {
set SessionId [findstr [HTTP::cookie "ASP.NET_SessionId"] 18 24]
log local0. "[IP::client_addr]:[TCP::client_port]: Response SessionId is: $SessionId from Set-Cookies: [HTTP::header values Set-Cookie]"
if { $SessionId != "" }{
persist add uie $SessionId 28800
log local0. "[IP::client_addr]:[TCP::client_port]: Persist record [persist lookup uie $SessionId]"
}
}