Help with JSESSIONID persistence

I opened a case with F5 support, they think iRule is fine its NTP issue with BIG-IP LTM 10.1. I turned off NTP and set dates manually to GMT to all my servers and BIG-IP. I can still reproduce this issue. I am using universal persistence and LTM drops persistent record after some time (say 9-10 minutes). I converted my iRule to be the simplest all I have is

when HTTP_RESPONSE {
 log "Server Address [IP::server_addr]" 
if { [HTTP::cookie exists "JSESSIONID"] } {
persist add uie [HTTP::cookie "JSESSIONID"] 3600
}
}
when HTTP_REQUEST {
log "request for [ HTTP::uri ] , when sessionId is -- [HTTP::cookie "JSESSIONID"] "
if { [HTTP::cookie exists "JSESSIONID"] } {
persist uie [HTTP::cookie "JSESSIONID"] 3600
}
} 

I would really appreciate if anyone has any clue about what's going on here. Thanks.