samba shares across different os's

[rac8006 at aol.com]

It has been a while since I've posted to this forum.  I hope I'm posting to
the correct forum.  Here is my problem.

I have a DLink DNS323 which uses smb1. This device is currently mapped as T:
and U; on my windows 10 Pro pc and laptop. I also have a WD My Cloud gen1
single disk using smb3 I think. I also have a PC running Debian Linux 12.5.
I want to copy all of the files from the DLink device to the WD device.
After copying all of the files. I unmapped the T: and U; shares of the DLink
device and mapped T: and U: from the WD device. After the mapping I checked
some of the folders and found that only the top level files and folders were
visible. Every folder was empty. After a log of fiddling I got most of the
folders to show files. Not sure what I finally did to get this almost
working. So I tried to mount the WD device to the Linux PC and got the same
problem of the folders being empty. 
My question is what do I need to do the be able to mount the WD device on
the windows PC and the Linux PC with all files available. I want to use the
Linux PC as backup for the WD device and use the WD device as backup for
some files from the Linux PC.