Pillagers do not spawn at outposts

I was playing on a server converted from 1.17.1 to 1.18.1 with someone and we found an outpost, but the outpost didn't spawn any pillagers.

I did some more research and tested on a single-player conversion world and a newly created single-player 1.18.1 world. Both worlds would create pillager outposts but pillagers would not spawn in them.