Disc drive doesn't show up in network

I have 2 networked computers. The second is used for business and the only time I connect to it is to transfer files back and forth. This doesn't happen often. Recently when I wanted to move a file, I found that my one drive (f drive) doesn't show up in the network. It is set up for sharing and does show up in my computer and device manager. From my computer, I can drag and drop or copy and paste files to the other computer through the network, but it's a lot of extra steps. It doesn't show up on either side of the network. I did try removing the share and restarting the share, but no work. Any thoughts as to what I did or didn't do to make this happen? I did try a new network connection but that didn't help either.

Lynn