Has anybody had problems with the CircuPool union collars not fitting the bypass cell? They thread onto the real cell just fine, but they will not thread on the bypass cell more than a half turn before they bind. I thought maybe it was just dirty and cranked it with my hand a little and it took putting it in the hot water to get it off. The threads are clean and free of burrs or visible defects. The thread pitch is not obviously different, but neither collar will thread whatsoever.