Keep in mind that when you reduce from an RV 50-amp shore receptacle to an RV 30-amp system using an adapter/pigtail/dogbone, the adapter/pigtail/dogbone simply dead-ends one of the 50-amp hot lines. The other 50-amp hot line continues into your RV through the adapter/pigtail/dogbone. Thus, you are getting 50 amps into your RV on your 30-amp wiring connection. The adapter/pigtail/dogbone does not reduce the potential 50-amp hot leg supply to 30 amps. Because you have a 30-amp RV on the receiving end of the power, I hope your RV's panel has a 30-amp breaker to reduce the potential 50-amp supply to 30 amps. Otherwise, if you have several electrical appliances turned on, your RV could be using all of the 50 amps available from one hot leg and possibly cause some hot wiring that's not built to carry 50 amps.
If I am wrong on this explanation, then I am sure someone will correct me. And if you correct me, then please explain what it is in an adapter/pigtail/dogbone that reduces the 50 amp hot leg going in to a 30 amp hot leg going out.