First, you will need to have connected the two ULTIMATE EARS BOOMs together at least one time. If you have not done that, then they won’t know to look for each other and will not connect to each other. The easiest way to do this is via the Double Up section of the ULTIMATE EARS BOOM app.
If they have already been Doubled Up together in the past, then perhaps you may have connected one of the two speakers to another phone or source device. In this case, you will need to Double Up again to reintroduce the two speakers to each other.
If that isn’t the case and your ULTIMATE EARS BOOM is not a polygamist then please make sure that both of your ULTIMATE EARS BOOMs are up to date with the new features. You can update your ULTIMATE EARS BOOM here.