Sorry, I was being a numpty and was thinking of TLSv1--not TLSv1.1. I couldn't find any docs on support for TLSv1.1 and none of the clients (openssl, curl, etc) I can find support it to try testing. I'd hazard a guess that LTM might not support v1.1. You might try opening a support case with F5 to check on this. If you do, can you reply back here with what you find?