The very first P doesnt conduct. The next one conducts with a long PR interval followed by the next P which doesnt conduct again. Then you have a conducting P wave followed again by a non-conducting one. I don't see lenghtening PR intervals here.

It seems like every other beat conducts, which is more like a Mobitz II. Other possibilities could be an AV block complicated by some premature junctional beats (5th+6th beats). Either they are premature junctional beats with an incidental overlying P wave or that is an extremely short PR interval with a delta wave (look in aVF).