Huge file size disparity between card reader vs cam transfer

[EdSnack]

I did a job yesterday filming with my X-H2s. Afterwards I downloaded the footage through the camera and a USBC cable direct to my iMac. Today I received a new Angelbird card reader and downloaded the same footage with this (it's extremely fast by the way). However I didn't expect to have any differences between the downloaded shots, but there is a massive difference in file size. The clip downloaded via the camera was 4.29gb the same clip downloaded via the Angelbird card reader is 25.3gb? Quicktime Inspector says they're the same specs, anybody know what this is about?

[Greybeard]

This is about a limit of 4GB (binary GB) in transferring using the cable - as you have noted the workaround is to use a card reader.

Its not clear if this is a FujiFilm issue or an Apple issue - or both.

FujiFilm could do a better job of making this well known as it just happens without any error message and it isn't obvious it has happened until you try and run the chopped file (or look at the size).