Electronic stylus force gauge question

I recently bought my first electronic stylus force gauge. It's a generic type made in China, but looks and feels a surprisingly decent quality. It was purchased from Mehran at SoraSound for those who happen to have it.

I noticed that when I try to measure the VTF, the gauge begins to display a minus reading of -0.01-03 g as I'm lowering the tonearm to place the stylus on the black dot. It then displays a steady reading once the stylus is placed on the dot, which appears to be accurate by comparing with the Shure gauge I used in the past.

I make sure that the platter is secured so I'm not quite sure why the gauge displays the minus reading before the stylus lands in the measuring spot.

Has anyone else experienced this with their electronic gauge? I realize the minus value is arguably negligible, and the issue might be of no practical significance, but I'm trying to get my Delos to track as close to 1.75 as possible so I wonder whether I need to adjust for the minus value. I'm also curious why this is happening.