I'm pretty frustrated as I use Astropad professionally and have had to put things on hold for a few days for the type of work I'm needing to use it for.
I have a 13" macbook that is updated to version 10.10 and I am working with it plugged in via USB.
The only FAQ workaround I could find was to go into energy savings in the settings and uncheck "automatic graphics switching"-this does absolutely nothing. I have powered off and on my ipad and it didn't help. Both programs are fully updated on my ipad and on my computer.
Astropad's FAQ says its just "a bug" they're working on but this is super frustrating.
I should note that things occasionally flash on my ipad when I switch programs etc on my computer or if I actively try to use the apple pencil on the ipad, I just can't see any full screen and they never flash for more than a second.