pilot light shuts off after minutes

It sounds like you’ve already tried to clean your vent, but just to make 100% sure it’s not the issue you’ll want to disconnect it. First, make sure your vent is cleaned and the best way to do that is just run a cycle without the vent hose connected to the back of the dryer to see if things change. If your dryer still won’t dry properly, then this is a pretty common issue unfortunately and it means that your gas coils are starting to fatigue and need to be ordered and replaced. As the coils heat up, the unit stops opening the valve or can’t hold it open as long as intended because it gets weak. You just need to order and replace the 2 black cylinder gas coils located directly in front of the igniter.