For keeping track of your watch history:
Verify that the Apple TV box is still set to Use Playback History.
Settings﹥Apps﹥TV app﹥Use Playback History﹥On
Similar for any other device where you may watch Apple TV/Apple TV+ content.
Select apps that are programmed to be able to connect and Apple-approved to connect to the Apple TV app, those may also have their content (or some of it) listed in Up Next. Availability of supported apps in the Apple TV app - Apple Support
Potentially connected apps have an on-off setting for this integration in: Settings﹥Apps﹥TV app﹥[ᴄᴏɴɴᴇᴄᴛ ᴛᴏ ᴛᴠ] …
Content may be available from multiple content providers. To select the preferred content provider, select that one on the details page of a movie or TV show, when scrolled down to How to Watch.
If the issue persist after checking the above, then try signing out of your account, then immediately sign in again, to refresh the account properties. If the issue persist even after that, then please contact the Apple Support staff for further assistance.