Let me be the first to welcome you to iRV2!
Just a wild guess, but it sounds to me like the DRL's are tripping a circuit breaker. After they're on for a while, the circuit breaker gets hot and trips off, then once it's off for a while it cools down and you can turn them back on until it heats up, etc. Maybe replace the defective breaker?
2005 Itasca Sunova 34A
2004 Jeep Grand Cherokee Overland