[2021] Muting people on PS4 has been busted for a long time.

Hey! Can you try clearing both your SMITE game cache/save data and then hard power cycling your PS4 to see if that fixes it for you?

• On the system home menu select settings.
• Select Application Saved Data Management
• Select Saved Data in System Storage.
• Select Delete.
• Select SMITE
• Select Settings and chose delete.

Then uninstall SMITE

After SMITE is uninstalled power cycle your console by shutting it down(not rest mode), waiting 30 seconds then turning it back on. After you've power cycled re-install SMITE.