SSL Handshake failed for TCP - Android Application Request

RealM From what I have seen in the past between mobile devices is some of them tend to send the request with a host field value of "example.com:443" instead of "example.com" and sometimes iRules and things such as this do not interpret those as the same string causing a failure without prompting you to accept that the SSL certificate doesn't match what you are sending. If the SSL chain is indeed the issue you can feed your FQDN to the following online tool and it will tell you if it chains out properly and rule out the possibility of that being the issue. You might take this opportunity to run a tcpdump on the F5 for your android user and see what that shows with the connection and where it gets to in the SSL handshake process.

https://www.sslshopper.com/ssl-checker.html