Some while ago, on a photo expedition to Blackville, unwisely I did not look at the filter on my camera lens. I'd expected like all the others, it was Hoya. It was only later when I saw the images that it became apparent that what was on there was cheap trash. It was some other brand and it was awful.
Lots of halation, lack of definition and loss of color in the image and all because of a cheap-ass ProMaster polarising filter. It didn't help also that the lens hood on the lens was pretty ineffective. As a general rule, wide-angle lens hoods are almost useless. Far better to hold up a hat between the sun and the lens when shooting into the light.
The moral of the story - toss out all the low-end filters in your collection. They're utter trash and the only person that's not deluded into believing they actually work is the person that bought them. The best of the cheaper brands is Hoya. Hoya is not perfect but it's a darned sight better than ProMaster.