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Try this. To eliminate any chance your problems are focus-point-related, select only the center point. Make sure your red focus point indicator is turned on. Then adjust your lens to be out of focus, and on the infinity side of in-focus. Get it as close as possible. When you want to shoot, put the center point on an area with adequate contrast and roll the focus away from infinity. When the center point flashes, shoot that instant. Practice doing that again and again in the lowest light you plan to shoot in. Concentrate on shooting quickly without moving the camera at all. The whole procedure is a bit of a knack. I learned to do it as a photo journalist in the 1970s, before auto focus. Then, of course, we had split prisms.
Doing it that way turned my Zeiss 35 f/1.4 from hit-or-miss into a super-reliable performer, even with moderately in-motion subjects. I still prefer the Canon for subjects in vigorous motion, howeverócan't roll that damped Zeiss focus ring fast enough. They are both great for image quality. I give the IQ edge to the Zeiss shooting into the light, and make it about even otherwise. But if you can master the manual focus technique, I think you may find the Zeiss a better bet at the widest apertures. Not a huge difference, but more keepers at f/1.4.
Also, where your subject matter permits (usually outdoors), using hyperfocal technique solves the problem.