How to fix that

Gas - smell if gas is coming out and turn lights out and see if ignitor is working ,
Electric- check the wire plug connecting to burner element .
Then resubmitt your question

there may be a loose connection in either the pipe or on the burner rings on the surface. Some stoves have a safety cutoff if gas supply is interrupted to avoid prolonged gas supply.

Sounds like the switch for that burner needs to be replaced. Its possible that something else may be shorting out but usually its just the switch. Your ranges burners and switches are standard switches and burners for this type of range so the switch should fix it. Hope that helps.

I have a lg electric dual convection range (Model # lre30757st) and the front left burner turns on and off on its own. (It will not remain off.)

What has happened is there is a surface thermastat built into the burner. You will have to replace that burner. This is a popular repair I have to do often.

It sounds like the left front control or element has a high resistance short.

The Viking manual says that an ignitor that continues to try to light even after the burner has been lit indicates improper grounding, and that an electrician should be consulted.

Perhaps you could try to replace the ignitor, and see if that fixes the problem?

I have a similar age, 6-burner 36" rangetop.

It has a bad element that needs to be replaced

Look at the back of your range there should be schemetic for your power control board. look for defective burner wire going into relay. There should be 5 relays in rows. Realy is the problem. I had the same problem with my front left burner stuck on high.
After replacing everything works okay.

Most likely the switch has welded closed