Time Machine not backing up server files after Sonoma update

Hi, I upgraded to Sonoma today, and most of it seems to be ok. However, I store the majority of my important documents on my desktop computer upstairs, and my Macbook is connected to that. Before I upgraded to Sonoma from Monterey, my Time Machine would back up ALL my files, including those on the server. And there are a lot! As I said, I keep my most important documents there, and not stored locally on my Macbook. When I open the link to browse time machine backups, the only files I can see (going all the way back to 2021) are the local desktop files, NOT my server files. And while in that mode, the "server" option is grayed out. I do have other backup options, but I still want my Time Machine to do what it's supposed to do. Any thoughts? I'm not super technical, but I can certainly follow directions to try different things. Thank you.