When processing large files, progress bar is not updated

[DavidUnderdown]

Having recently received two batches of videos from a government department it appears that when processing a relatively small number of large files the progress bar does not update for some reason. File sizes were in the range of 10s of gigabytes, one batch had 36 files, the other 45 files, average file size 32 gb. The CSV files eventually passed validation, but the progress bar never changed from the original blank state. Both fileExists and checksum checks were being used in the schema

[DavidUnderdown]

Needs confirmation as to whether this is still an issue