I have the same problem just replaced the thermocouple still does not stay alight as soon as you release the gas start knob it goes out. Fires up straight away gas burner roars away goes out as soon as you release the knob.
Back to the drawing board!!
can not find any useful info on the net except call out a gas man I can replace all the the major parts and still come out cheaper than a man coming out!!
Nortonick
July 2020