I have both 123.py and 456.py under scripts/. In H21 both run, but in H22 only 123.py runs? Is something changed? The doc (https://www.sidefx.com/docs/houdini/hom/locations.html) still says 456.py is a thing.

I have had the same issue, did you make a bug report? I'm thinking I'll make one.

I heard from SideFX Support that this problem was solved in Houdini22.0.386.

I'm using "uiready.py" [www.sidefx.com] as a stopgap.

I had the same issue, turned out the 456.py of the Labs was taking over.

Check if there is a file in here (for Windows), if so rename it and maybe copy its contents to your own file:

C:\Program Files\Side Effects Software\sidefx_packages\SideFXLabs22.0\scripts/456.py