File transfer cuts out halfway through

So I’m trying to clear up my iPhone storage by plugging it into my computer and mass-transferring photos onto a usb drive, but it cuts out halfway and only a fraction of the photos make it over.

For example, I’ll select a folder that contains 293 items and try to transfer it, but it randomly stops and only 120 or so photos actually make it through.

I tried formatting it to exFAT but that doesn’t work. And yes, my usb is plenty big enough.