I do not have a Pro series grill, but if you have used the grill for 5-6+ years with no issues, you have done well. If you continue to see issues, it's time to do some troubleshooting. Parts like the fire pot, hot rod ignitor, RTD thermocouple, auger and motor, fan and motor can go bad over time. Fortunately, these parts are available can be replaced by the user, with moderate difficulty.
Based on your description of the problem, I would suggest removing the grill grates, drip tray and flame shield from the grill while it is cool. Make sure you clean the firepot, grease chute, and smokestack thoroughly to remove any buildup. Be sure to wipe the RTD thermocouple to remove any buildup of grease and debris, but be careful not to damage it.
Then with the internal parts removed, prime the auger to add pellets to the firepot and then ignite the grill with the lid open. Listen to the auger and the fan, making note of anything that does not sound normal. Observe what is happening in the fire pot. Obviously, with the lid open, the grill cannot come up to temperature, but you can see if the auger and fan are working properly to stoke the fire..
If everything looks good, allow the grill to cool. Replace the flame shield, drip tray and grates and then try to start the grill normally.
If the grill still malfunctions, the next thing you might do is replace the RTD thermocouple. Be sure to get the right one for your grill model as there are several types.
I hope this will help. Good luck! Please come back and tell us what you find.
