In the 1.20.10.20 Preview behavior pack folders several entity behavior json files are in the root folder instead of the \entities folder. This probably makes them ineffective.

To reproduce, navigate to
C:\Program Files\WindowsApps\Microsoft.MinecraftWindowsBeta_1.20.1020.0_x64__8wekyb3d8bbwe\data\behavior_packs\vanilla_1.20.10

and observe the misplaced files.