search index question

I had search index file that covered about 30,000 files. Files were local but also synced to OneDrive. The index worked as expected - fantastic resource. I recently changed to another OneDrive path. Now when I try to create a new search index i seem to get a random sampling of about 5000 files. Everything builds fine - its just 5,000 of the 30,000 though. Path lengths are not signficantly different. I'm using file paths directly on the computer - not in the cloud. Any ideas what the issue could be?