As was mentioned, you should definitely look into troubleshooting your installation. Most of the time, it is simply that the Equalizer APO configuration has not been installed on the actual playback device that you are currently using.
With that said, start here to get back to the basics:
Manson2 t1_iydy5o8 wrote
Eq apo works. Troubleshoot your installation and switch to SFX/MFX or LFX/GFX. Especially if you're on windows 10+. It's goofy like that.