How can I do this? Its annoying that posters keep changing by themselves. It makes scanning the library constantly different. Also if you’ve set metadata to correct a wrong auto assumption it often returns to that wrong assumption again!
What type of device are you streaming from? Do you know if you’re using UPnP or DLNA by chance?
Normally, Infuse won’t attempt to update or rematch items once they have been linked to a title on TMDB, but if you are using of the connection options mentioned above these servers have a tendency to reset/refresh the file lists from time to time which can cause Infuse to treat these as new files instead of existing files.
Also, if you are using an Apple TV you may consider using the Cloud Backup feature as this allows Infuse to quickly restore the library if your device is running low and space and starts clearing app data from Infuse and other apps.