Today has been my first day with the Phantom 4 Pro. Playing with all the settings indoors, as well as doing a few test flights. One thing that I've noticed is that my picture will go completely black for just a split second, then render back with visible blocks. It seems that it was dropping out more when indoors. Could this be due to wifi interference? Anybody else seeing their picture drop too?

could be from wifi, turn it off and try it !

Good advice is not to test anything indoors, get outside and test it otherwise you will get unpredictable results.

When testing outside and setup your phone as airplane mode, how about the performance?
IF it persists, please confirm what mobile device you are using and DJI GO version.

When I mentioned wifi interference, I was referring to the routers around me. My phone wifi has been turned off as recommended. I still did get a couple of drops while outside in airplane mode. I'm going to test again sometime today to see if it persists. I'm using the Motorola Moto Z Droid, with DJI GO 4.0.0. I just ordered a used Nexus 7 tablet for a bigger screen, so I will be able to tell if it is the device causing it or not.