I will say up front that this is a terrible bug report. If, indeed, there is a bug. I'm just reporting my experience.
For the better part of a decade, I've been using tip tap as a "close tab" gesture in Safari. To be clear, this is the left "one-finger" tip tap. Two fingers are active on the pad. The right finger remains on the pad and the left finger taps.
Two-finger drag has long been the standard macOS scroll gesture, or at least, that's how I have things configured. I'm sure you can appreciate how fine a line there is between two-finger scrolling and one-finger tip-tapping. Nevertheless, BTT has always performed like a champ. I've had to adjust the "TipTap sensitivity" parameter, but with the right value, it used to work really well and do a great job of discriminating tip taps from scroll gestures.
More recently, there seems to be no value of TipTap sensitivity that works for me. Even at the best value, spurious activations of the tip tap gesture and failure to activate on an intentional tip tap both occur frequently.
Has the tip-tapping or trackpad code been tweaked recently in a way that might impact this?
To complicate matters, I switched a couple of months ago from a Magic Trackpad version 1 to a Magic Trackpad version 2. Other than the problem outlined above, I don't notice much difference between them. But, suspiciously, my problems with tip tap did start in the same general time frame as the switch. It's entirely possible that the V2 trackpad screws things up with higher sensitivity to hovering fingers.
Apple M1 Max, 32 GB RAM
BTT 4.077 (2293)
BTT lists the gesture as "TipTap Left (1 finger fix)". I'm not sure what the "1 finger fix" is all about - I don't see a "turn on 1 finger fixes" option elsewhere, and there is no version without "1 finger fix".