So, I ended up clearing the app cache and app data, clearing my phone's RAM, uninstalling Poweramp, rebooting my phone and then reinstalling it again seems to have fixed it for me. I did experience one short glitch, but then it recovered and has since been working fine. Hallelujah! Hope the issue doesn't reappear again.
I did try exporting the app settings before the uninstall, so I wouldn't have to go through the long process of configuring the app and EQ custom presets again, however when I tried to import the settings from the export file it failed. Oh well.