Hi,
[SOLVED]
I was able to fix this for me. Hope this helps someone else.
I got the "device unreachable error" while trying to transfer videos from my Samsung S23 to Windows laptop. Funny enough, I was able to transfer photos without any problem.
I was able to fix this by clicking on the "USB file transfer turned on" from the notifications. This opened "USB Settings". When I scrolled down to the bottom, there was "File transfer options" settings. I turned on Transcode exported video option and this fixed the issue.
Hope this helps.
Cheers!