It varies the wiper speed and even stops and starts somewhat correctly, but it frequently is not wiping after rain build up and sometimes keeps a fast speed after rain became drizzle. Is that normal?

I removed the plastic cover and jiggled the sensor and it seemed to help somewhat (and also triggers a wipe each moment that I initially touch it) but it did not completely fix the issue - the glue-goop between the sensor and window looks fairly messed up with many cracks/seams within the goop (looking through the windshield from the outside of the car.)

Recommendations?