I don't know if it was intentional but far more dungeons are generating underground than in 1.17 and prior. In some worlds I counted 6 or more dungeons within my field of vision underground in spectator mode.
Seems consistent in multiple worlds, although some worlds you have to look much closer to find them, depending on the biomes.
See video for example
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Increased the amount of dungeons, especially below height 0
https://www.minecraft.net/en-us/article/minecraft-snapshot-21w40a
Mojang in previous snapshots for 1.18 had made dungeons more common under y-level 0. I would not call this a bug based on the evidence you have provided (not saying its useless). Take this with a grain of salt, but I think this isn't a bug and it will be just perhaps listed as "Working as Intended."