In version 11.1 the use of TraditionalForm as a Preference option has been deleted. Changing
Changing the CommonDefaultFormatTypes in Options: Cell Options section from StandardForm to TraditionalForm for both Input and Output does not result in a TraditionalForm for the Input cell. You still need to right click and Convert the Input Cell or //TraditionalForm.
Is there a way to have the Input convert to TraditionalForm automatically on hitting the enter key?