Installing a detent ball, we always referred to them as vlier screws or plunger screws, would probably help.
But I can't figure out why you would be having that problem in the first place, unless your mill is sitting on a floor that is 20 or 30 degrees out of level.
I ran dozens of different bridgeports and clones over the years and I can't recall having that happen more than a few times, maybe when I had a corncob cutter in a little too deep or something like that.
I wonder if the gibs are excessively loose.
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