I note that the capture was gathered with the scope channel set to AC. Although these inductive position sensors do output a AC signal they are best measured with the Pico set to DC and the black lead directly secured to battery minus. AC coupling this particular measurement has a potential to hide ...
I have taken measurements between timeline 600 - 620 of your waveform where a frequency drop of about 50% is displayed by the math channel. This is not a true reflection of the wheel speed reported within that time frame neither does it indicate a vehicle / abs fault. A 50% instantaneous speed drop ...