In ArcGIS Pro 3.1.2 I am unable to project web layers. This includes layers from ArcGIS Online (including the Living Atlas), and from our Enterprise Portal (both hosted and reference feature layers). I get "Error 000185: This data type is not supported" when adding such layers to the Project tool.
The documentation makes no mention of this limitation, but I feel like this used to work just fine. I can't find any proof that I've done it in the past, but this is a common enough workflow that there's no way I just didn't notice until now, right?
For now the workaround is writing my own tool that emulates Project, but I'd like to see if other people are having this problem. I can share my code if so.