Question

Before I launch Studio One, I hear playback from everything through my audio interface. Then I launch a session in Studio One, and I hear the playback from my browser through the speakers from my computer screen/tv. I hear the playback through my audio interface from Studio One. But it disconnects it from everything else. I went to sound settings on my PC and My UAD Apollo is selected.

Answer 1

Since you mention PC, I am safe to assume you work on Windows 10. 

- Make sure your sound settings in Windows 10 match those with your audio interface program. ( Bitrate, sample rate, etc. )  
Right click loudspeaker on taskbar and select sounds. In both Play and Record(Output/Input) tabs, right click your Apollo interface          and select properties. Go to advanced and select the bitrate you want to use. 24 bit 44.1 and 24 bit 48 kHz are normally used. 
Make sure your Apollo is also set to the same bitrate in Universal Audio. When starting a project in Studio One, make sure the track setup also have the same bitrate setup.  

- Optional, and to be safe, is go back to your windows sound settings. 
Right click loudspeaker again and go to output tab. Right click your monitor/TV audio out and deactivate it. (That is, if you do not plan to use it. ) 

This might already solve your issue. If not, you can try to release your audio device when Studio One is in the background.
- When opening Studio One, go to Audio configuration, Audio Setup and check 'Release audio device in background'

Let's see how this works out for you. 

Answer 2

Thanks for your response. The release audio device in background, did solve it. But it takes a few seconds every time I switch back and forth between Studio One and my browser, and I hear a clicking noise on my Apollo Duo. Is that normal?