@sjmmwanza Hello, in the Gallery there is an option to Hide or Show Albums. Check if the photos are not found, by chance in one of the unintentionally hidden albums.
Another thing to check is to check if you are logged into One Drive. Greetings.
@sjmmwanza Hi, go to Gallery , the three dots / Hide or show albums, check if you have any of the hidden albums.
The following: go to Phone / Cloud and Accounts Settings and find the ONEDrive account. The Gallery is currently syncing with ONEDrive, so log in with your ONEDrive account and check.