Birzman Velocity pump

Anyone have one of these?

I just received one I’d ordered but can’t seem to get a proper seal. I’ve followed the directions exactly but the thing just leaks air. Very frustrating. I’m about to send it back.

I think I figured it out - it only fails to seal on the valves on my wife’s roadie, which seem to be slightly narrower around the head than the other valves in the house. Works perfectly on all the other bikes - presta and schrader. Now to take out the tubes and figure out what they are (can’t remember what I put in there).