Hi Robert Pollock,
Following the link you provided I was able to download a valid item.pitemx file and open it up in ArcGIS Pro (version 2.3.3) - see screendump below.
So: no, I do not have the same problem... 🙂
Please tell us a little more about your issue. Could you open the item.pitemx file in a proper text editor (e.g. Notepad++)? What does it look like? What error messages do you get when trying to open it with ArcGIS Pro?
Again, everything works fine for me.
HTH,
Egge-Jan