The old faithful turn it off at the plug and then back on did the trick for me, every piece of electronics goes wrong at some point.
Worked for me thanks for the advice I found looking at your forum 😁😁😁😁
Had same problem. Also heard buzzing noise from box when near to it. I waggled and pushed all the cables, recycled power and the TV guide came back. Buzzing noise also stopped. Guess it was cable connection problem.
The buzzing noise that you are hearing might be the smart box inbuilt fan which would vary in speed depending on the internal temperature of the smart box.