Pyramid Electric Strings 010-046 Light

Pyramid make some of my favorite strings, both for guitar and bass. Unfortunately I also have a problem with fret buzz when using some of their strings. I can set up the guitar/bass perfectly and still get an unacceptable amount of fret buzz. I'm obviously talking about guitars/basses where other strings of a similar type from other manufacturers works perfectly.

I have no idea what's causing this. Maybe Pyramid use a thinner, more flexible core that vibrates with a larger amplitude? It's still a bit weird. It's not like we're talking about round core vs hex core here. When I compare these strings with similar roundwound, hex core, nickle plated steel strings from other manufacturers the Pyramids ALWAYS have more fret buzz than ANY other strings when I set up the guitar for the same action, relief, etc.

Basically, I can use these strings on SOME guitars (and I do because I love how they sound) but on other guitars they are useless to me.