I have been loading kml files obtained from Open Street map (using overpass turbo) into ArcGIS Pro and it is not symbolising all the individual items as a Yellow Pin, with half of my list blank. I have tried a number of ways to amend this and now have a red box instead of a Yellow Pin. Has anyone seen this before and know how to fix please to show all records as a Yellow pin?
What kinds of data are you pulling from OSM? There are much more efficient ways to do this, and if it's something you anticipate doing with any frequency, it's well worth your time to look at some of the many tools for processing OSM data.
Personally, I use imposm against a Geofabrik download to set up my database of OSM elements, and then by defining a limitto geometry that's roughly the area I'm interested in, I can have a regional extract of OSM data that's kept as up-to-date as I want it.
To give more specific examples, I have a database table that is specific to Illinois road routes. When I spot errors or gaps in the data, I can edit OSM and see my database reflect those changes within minutes.
I also have a table that holds anything with an indoor tag on it, things that the typical OSM renderers and non-OSM basemaps do not include. With that data, I can make some really detailed indoor maps, which is something I like to do in my spare time.