Time Machine Starts Over
I have an old IMac using Catalina. Since I went up to Catalina from Mojave every time I do a backup using my Time Machine which is just as old it starts completely from the beginning again each time. It will do a complete full backup over several hours to complete if I leave automatically backup checked and tell me a new backup is needed . I do not know where to look for help with this problem. I am hoping you have an answer for me. Thank You very much for your time.
Emil
Windows, Windows 6