A scanner and a printer are two different devices sharing one case. The printer side can work perfectly while the scanner side fails, because they use different drivers, different connections and different software.
The most common cause is a missing or corrupted driver. Operating system updates sometimes remove older scanner drivers, and the printer keeps working because it uses a different, more modern driver path.
Connection type matters. A scanner connected over a network may be visible to print but not to scan, because scanning requires a two-way conversation that some network setups block. A direct USB connection often works when wireless scanning does not.
Scanning software can also be the issue. The manufacturer app and the operating system scanning interface use different paths, so if one fails it is worth trying the other before reinstalling anything.