I don't believe this is only for realms. I play a private survival world and the same issue occurs for me. I'm not on pc, I'm on playstation 4.
Even prior to 1.16 my old world was extremely scarce in patrols. This new world has had 1 patrol and since then nothing. I have added vantage points around my village, in my village, and beyond my village. Camped out away from my village. Made sure golems were not killing patrols. The zombies pose more of a treat to my village than the raiding npc themselves at the moment.
My minecart with hoppers keep disappearing in enclosed tracts. The minecart goes back and forth collecting. They just vanish. All of them. (I only have 7 around the village) but they all vanish at the same time which is annoying use of iron. This is happening on ps4, realms