[waltjp]

I had a problem with LH vs. RH batters that was brought to may attention by a few trusted observers. My strike zone for a LH batter was wider than that for a RH batter. I started looking for a reason and I concluded the following:

Most pitchers are right handed. With a right handed batter I'd generally line up with my nose on the inside of the plate, which would give me a view of the pitcher's release point and allow me to track the ball through the strike zone.

With a left handed batter I was lining up a couple inches further inside because a right handed pitcher's release point wasn't blocked by the batter. This allowed me to see the strike zone at a wider angle. The result was that I was widening the zone for a left handed batter.

Realizing that I wasn't setting up in the same relative position for right handed and left handed batters has allowed me to make adjustments and call a consistent zone for batters from both sides.

My advice would be to check your positioning and head location.