I have an older project with face-based light fixtures and diffusers. All worked fine in R2022.
I upgraded the project to R2023 since I need to make some changes. Now the very same families (not reloaded) can't be placed face-based. The option to switch to face-based are grayed out. This isn't an issue on floor plans. I tried multiple type of families, they all seem to have that behavior. Looks like something is wrong with ceiling views.
I created a new ceiling view, same thing.
the former families (face based and hosted to the ceiling) also don't let me select a new host that is face-based. when I find a new host, it also only works plane-based.
When I click "OK" and the pop-up goes away, the placement options un-gray for a second.
any tricks to work around this? I can create a work plane since this is just a small change. I guess. but if this was a larger project, this sure wouldn't work well.

Edit: I created a reference plane. Then I placed a diffuser on the reference plane. AFTER THAT I was able to place new families and am able to select the placement method (not grayed out anymore). I even could change the host of the family I had placed on that reference plane. My best guess is this shook something loose that got wrong.
Hope this helps someone who runs into this.
Revit version: R2025.4