I had a Dell with Ubuntu 18.04 plugged into my router with Ethernet, and a Windows 10 Dell using wireless. The Windows computer could access files on shared folders in the Ubuntu computer. It didn't work vice versa but I didn't care and figured it was a Windows defect. Now they are switched, with the Windows 10 on Ethernet, and it doesn't even "see" the files on the Ubuntu computer anymore (and still doesn't work the other way). Is there something I need to do in Ubuntu to make the folders recognizable again? Some Samba thing?