There have been quite a few posts recently about fixes for the DTS Headphone App not working on Windows 10. In particular, most people have a variation of the ASUS Tuf FX505 gaming laptop. This solution should also work for other laptops as well.
I've found several solutions with confusing answers, however I came across this answer that instantly resolved the issue!!!
Step 1: Uninstall DTS Headphone:X 1.1 on windows
Step 2: Go to Device Manager and make sure your audio drivers have been updated.
Type 'Device Manager' in windows search and open it.
Go down to Sound, Video and Game Controllers, right click Realtek Audio and click update driver.
If it prompts you to restart your pc then restart.
Step 3: Download the later DTS driver from your PC's support site. In this instance I went to the ASUS Support Site.
Step 4: Unzip the driver folder. Right click on DTS_install_HPXv1 and run as administrator.
Step 5: Go back into the ASUS Support and you'll see another DTS Headphone download that's available. It should take you through to the Microsoft Store to install the DTS Headphone app.
Step 6: Once that's installed, go to the 'DTS_HPXv1_UWP_APO3x_Asus_EXT_22.214.171.124_RS5' folder in the driver download file and copy the file 'dtsapo3oemconfig.xml'.
Step 7: Go to 'C:\Windows\System32\DTS\PC\APO3x' and paste the file in there.
IT SHOULD NOW WORK!!! Remember to restart your pc at the end of this. I hope you found this helpful, best of luck and happy listening!