Issue is 100% caused by FxSound, ever since removing it, I have no issues. Perhaps look for another audio enhancing app and test with it. The reason it happens is that it recognises both your own audio and the audio enhance from FxSound, since Discord picks both of them up, they share both audios. Also disabling FxSound through the power off button in the app didn’t work, it had to be a disabling of the audio device through Control Panel.
If there was a way to ignore picking up of the sound from Discord or perhaps, FxSound not acting as a second Audio device, would work I imagine. I also tried with Speakers, Headphones - On/Off, different presets. Nothing worked until I disabled it and it’s all okay now.