The STAAD.Pro Connect Edition Update 1 is supposed to have the AISC 360-16 code. However when I go to the Design page, I do not see the code in the list of available codes? Can you please tell me why ?

Possibly the program is still using the application INI from a previous version of STAAD.Pro Connect Edition.

Please follow the steps below to fix the issue 

1. Exit all running sessions of STAAD.Pro application.
2. Delete the folder C:\Users\<User.Name>\AppData\Local\Bentley\Engineering\STAAD.Pro CONNECT Edition\Default. Note that <User.Name> is to be replaced by actual user profile name.
3. Restart STAAD.Pro application.

This time (and going forward), you should see AISC 360-16 code listed.