The behavior you described above should not be happening. Please try refreshing your application settings as outlined below to see if it goes away afterward...
- Go to Help>Open Settings folder.
- Copy the contents of the folder over to a folder on your desktop.
- Close S1 and delete the contents of the settings folder with the exception of the user.license file as well as the "Extensions" folder.
- Open S1 and go to Studio One>Options (Preferences on a Mac) to reconfigure your settings.
- Test to see if the problem is resolved. If it is not, please feel free to copy your settings files back over from the backup that you created in step 2.
*If you are missing presets or Sound Sets after doing this, simply double-click one of your Sound Sets under Documents>Studio One>Sound Sets.
If doing that doesn't cure the problem, please create a support ticket and (if possible) also include a short video or animated gif showing it in real time and be as descriptive as possible as relates to what's being used, what instrument for example if the Fat Channel is on an instrument track.