Oven stops heater over 150F

Oven spark ignitor initially did not work and smelled gas when tried to turn on oven. Changed the spark ignitor. Then oven turns on, but stopped heating over 150F. Already changed the ignitor module part#618624. Still did not go above 150F. Checked the temp sensor working fine. Ordered the PC board # 709786, still does not work. It seems like the gas shuts off after it reaches over 150F. Can it be the gas safety valve problem?