I use Xikar butane, mainly. I've used various, cheaper, and "tobacco shop" brands when traveling. One negative thing I've noticed with some of these, is they do seem to degrade the lighter. I do believe there's been a time or two where I've asked myself the same question you pose here - is this cheap butane giving me a bad experience, or did I F-up my cigar - and, honestly, cannot say which it was with certainty.

I'd say: if you're noticing something different, and the only thing you've changed is your butane brand, then it's time to change back or go to another brand.