Ubuntu 24.2.2 LibreOffice Trouble opening databases

I am running Ubuntu 24.2.2 LibreOffice. I am trying to open my four databases, one at a time, which are located in /home//<filename.odb>. When I attempt to open a new database in LibreOffice Base, two of them appear in the drop down box and two don’t. When I try to USE each of the four of them in mysql at the command line, I get the following message ERROR 1049 (42000): Unknown database ‘filename.odb’. At the Ubuntu 24.2.2 command line, the files are listed in the Home directory “/home// “. I have spent a couple days trying to determine why the other two don’t open, but with no joy. I would appreciate a pointer in the right direction. Thank you.