BIGIP unable to send tcp/udp packets to syslog servers

Hello prajith_nsg , I see that you're using a Stateless virtual server. Port translation setting is not supported and is known to not work as expected if enabled on the stateless virtual server. (Check this KB for reference)

You can run this command to display the connection table and confirm if port translation is happening or not while the connection is active 

tmsh show /sys connection cs-client-addr <your ec2-user client address 10-0-xx-xx> 


tmsh show /sys connection cs-client-addr 10.0.113.100
Sys::Connections
10.0.113.100:49236  10.0.113.200:5555  10.0.113.100:61501  192.168.1.152:80  tcp  4  (tmm: 0)  none  none
Total records returned: 1

In this example, Client information below: 
SRC IP ADDRESS / PORT (Client to F5): 10.0.113.100:49236
DST IP ADDRESS / PORT (Client to F5): 10.0.113.200:5555

BIG-IP will receive this request and after making a load balance decision it will initiate a connection with the pool member with the following details:
SRC IP ADDRESS / PORT (F5 to server) : 10.0.113.100:61501
DST IP ADDRESS / PORT (F5 to server) : 192.168.1.152:80

If you need port translation to be effective, you should run a different type of virtual server -- fastL4 should work IMO.
If it's not mandatory, you can try changing VS port to 5514 and see if client test is being forwarded as intended.