You haven't mentioned if cheats are working in any other saves, but here are some troubleshooting tips:
Regardless if you're using mods or not, delete the localthumbcache.package from inside the Sims 4 folder and try again. This helps troubleshoot game issues.
Make sure you don't have any mods that may interfere with trying to use the cheat console or cheats. For example the UI Cheats Extension is known to cause issues with the cheats.
Try using cheats in a different saved game or household.
Sometimes traveling to another lot and testing to see if the cheat works helps.
Repairing the game may help. - In Origin > Games Library > Right-click on Sims 4 and select Repair.