It looks like there was a change from 4.5 to 4.6 which makes it so it now defaults to Development instead of picking a configuration based on the configuration of the editor. This was made at the same time as the new Simple Profiles. I’ll log this as a regression and talk to the engineer who made the change.
Ok after talking with the engineer, we have decided to add some settings for the build configuration for Launch On in a future release. In the mean time, for your specific case, since it looks like you are building the editor anyway, if you were to go to Source/Developer/LauncherServices/Private/Profiles/LauncherProfile.h and in the SetDefaults method, you can change the BuildConfiguration line to be the following: