I don't have much experience with LPM. I did a quick test a couple of years ago. But I recall that it uses some specific layers for its parts. Check if there is one for Hotspots.
Hope this helps.
I'm just playing with LPM and was very frustrated with the error messages until i realised you need to add a Level Dimension Marker for each 2d and 3d symbol type you use. Its not documented as far as I can see although starting a new file using a Library Part Maker Template 24.tpl makes it obvious.