Scanning large USB HD stalls (4Tb NTFS)

Running Volumio 2.246 on Pi 3B
Audio plays well for all files catalogued
Extended file format support =off

I am indexing a 4TB external USB drive, formatted in NTFS. There seems to be certain files in a folder that stall the indexing. Indexing initially always stalled at 34.7K Tracks. By renaming a folder so that its in last alphanumerically, I believe I have isolated the issue to a certain folder. Currently stalled at 90.4K tracks.

Are there limits to how many files can be indexed? If not, how can I find which file is causing the issue, logging?

I know I am indexing a great number of files but the point of this project is to simply sync and carry a portable system to the log cabin. I need to avoid curating the music library, at least for the next 6 month as I currently have a medical issue that constrains screen time.

Many thanks,

Has anyone else hit limitations on number of tracks?

Thanks for your help.