Pillager Patrols were consistently spawning before I set up a village in my base and completed a raid. I had at least 30 in the several days before then, but since then I have not had any Pillager Patrols spawn in at all. I have left the area and come back, with no change.

Edit: I removed the beds, killing the village, and within 2 hours Pillager Patrols were spawning again.