[Uncle Skeleton]

I'm not quite sure of a good way to describe this...
Here's a play-by-play
1. My external usb drive (formatted exfat by the mac) has files/folders A, B, C, and both computers R/W them
2. On my mac, I copy file D to the drive, so now it's A, B, C, D
3. Now on win10, it shows as A, B, C, but no D. I try hitting the "refresh" in explorer, and create a new folder, but file D is still invisible.
4. Move the drive back to the Mac, and it says A, B, C, D, and the new folder that win10 created.
5. Now move it back to win10 again, and now A, B, C, D and new folder are finally visible.

What is happening here? Or what's a good keyword to search for?

Thanks all

[reader50]

Windows once got snooty on me, not accepting an external formatted by a Mac. A leftover from Microsoft's days of breaking interoperability. So the problem might not happen if Windows formatted the drive.

I've never seen your specific problem though.

[subego]

I’m pretty sure Windows has a “show hidden files” switch.

Not so much a fix, but at least a tool to help along the way.

[Uncle Skeleton]

I tried the "hidden files" checkbox, didn't make a difference. The most streamlined version so far seems to be
copy files to usb drive on mac
plug drive in to windows
eject drive from windows
un/re-plug drive in windows
now the files are visible

Does windows have a way to re-mount a hard drive without getting up out of my chair to un/re-plug the usb connection?
I haven't tried reformatting the drive, because it's 3TB and full of files I want.