When my R1+ did this i went to a 0.6 nozzle and i put a new fan for my hot end because the heat was melting my filament before it got to the nozzle, and i didnt want to increase my speed more than i needed to. Also i see your printing at a 0.3 layer. With a 0.4 nozzle? I never could get a decent print with a 0.4 nozzle. A 0.5 nozzle at a 0.15 layer height made my prints amazing. And for stronger and faster prints i use a 0.8 nozzle now. Also i've recently added a fan to my extruder motor as it seemed to be really hot. Since i've done this i dont have random empty spots in my prints anymore. I still need to replace the extruder moter however.