I'm running Astroberry on a Rpi3b with generally good results. My camera is a Canon DSLR, and I frequently have an issue with blank frames. Tonight, for example, when I am using the capture module every other frame is blank. The good ones are good, but every other one is blank.
I sometimes see a similar issue when focusing, or plate solving. Sometimes restarting Ekos resolves the issue, but not this time.