How much scoop did you got ?
In my HELIX adventures, i got my fingerboard scooped by one luthier, then it got way too hard to play and I still had some issues with somes buzzes. If I pressed the string right after the nut and at the end of the fingerboard, I had a 3-4mm gap at the 7th position.
I got back to another luthier who planned the finderboard again to almost no scoop, I sure got back some better confort and more sustain. I realised that a good way to describe the buzz would be that he strings are producing some kind of a 'zing' at few spot, specially and almost only on the G strings.
The last luthier that saw my bass with the HELIX also thought that the string kind of sounded like a new string even after 4-5 weeks of uses, he suspected that it may get resolve by itself, but so far I saw 3 luthiers with the HELIXs on my bass and they all came to the conclusion that this 'zing' sound may also came from the way the string was made. I wonder if it just maybe faulty at this point.