A TLS Handshake from an application returns handshake_failure from Big-IP

I have a .Net 4.6.x service running on a Windows 2016 server which tries to connect to a VIP on a F5. SSL terminates on the F5.

A TLS Handshake: [Client Hello] from an application returns an [Alert] handshake_failure(40) from the F5.

BIG-IP 12.1.3.7 Build 0.0.2 Point Release 7

Client Hello:

Name    Value   Bit Offset  Bit Length  Type
version TLS 1.2 8   16  TLS.ProtocolVersion 
length  208 24  16  UInt16  
fragment    [Client Hello]  40  1664    ArrayValue`1    
[0] Client Hello            TLS.Handshake

Handshake Failure from F5: AlertLevel fatal(2) with AlertDescription handshake_failure(40)

Any suggestions on what I could look at? Thanks!