11.4.1 - Images missing from target export folder

11.4.1 - Windows 10, 3080ti, 64gb Ram

Imported 3800 raw files (cr3) into lightroom.

Exported compressed DNG to external drive

111 files were missing from the target folder.

Since the update to 11.4.1 from 11.4 there have been improvements in the performance of exports generally but I have to manually check every export to ensure my clients files are present.

Exporting the same files to multiple folders at the same time doesn't happen in parallel either.