It seems that your audio configuration needs to be adjusted outside of Pro Tools.
You will need to bypass the mixer in Universal Control to prevent a feedback loop from occurring.
Please ensure that you have installed the latest version of Universal Control from your PreSonus user account.
1. Open Universal Control.
2. Click on the Studio 1810 image to control the device.
3. In the top right hand corner of the UC window, select the Settings gear icon.
4. Under the System section, enable "Mixer Bypass" to disable mixer control.
While Mixer Bypass is active, your Studio-series interface will function as a simple I/O device for your DAW. When the mixer is bypassed, you must route audio to the desired output using its dedicated playback stream both for system playback (if desired) and DAW playback.
Additionally, to disable Universal Control from defaulting and having to make this change each time, below are instructions to disable.
Please follow the steps provided below if you wish to disable Universal Control as a Startup Program on Windows.
1. Open Universal Control
2. Click on "Settings"
3. Un-check "Run at Startup"