If you find the glow bar igniter glowing red and then fading off without burner ignition, the two solenoid coils on the gas valve are becoming weak and will need to be replaced. Now, if there is restriction in the vent system, the flame will not be drawn back towards the drum and the high limit thermostat will shut off the burner. The igniter will not attempt to come back on until the high limit thermostat cools and resets.
For testing purposes only, disconnect the vent hose from the back of the dryer and then see if the burner cycles off and on properly. If you find the igniter glowing and fading off without burner ignition, replace both solenoid coils on the gas valve. If it appears to be cycling correctly, the vent system is likely restricted.
The coils may test within specifications when cold but when they get hot from the current to open them, they become too weak to open the gas valve.
In order to access the gas solenoid coils, the front panel will have to be taken off.
NOTE: Disconnect the power cord from the power source before servicing.
Thanks go to Joey S