Clicking "Recenter" does not reset the view to the center but rather moves it in increments. Only after clicking it a bunch of times, the absolute center of the board (well almost absolute to 99%) will actually be in the middle of the Udon Graph View.
Note that I made sure that in my example the node is in the actual middle before moving the canvas and hitting "Recenter". It should have recentered afterward but the board only moved half the distance.
VRC: VRCSDK3-2019.12.21.16.01
UDON: UDONSDK-2019.12.22.12.32_Public