Glad you were able to try it. Overall I have really enjoyed using my Robobrew. It has led to me brewing more. Of course, the pandemic has had something to do with that too.
I find that the malt pipe drains slowly. It may require a less fine setting on the mill. But we always try to push what we can get away with, right? My last batch was nearly stuck also. I've only had one that was truly stuck. I had to dump the entire malt pipe of grain into the cooler that was my old mash tun, and let it drain from there. I usually start out boiling at least 6, sometimes 6.5+ gallons. It's hard to tell how much has drained into the kettle, since the malt pipe is in the way. I don't try to measure how much sparge water I use...just watch how full the kettle is and add more if I think I need to. Occasionally I overshoot. At this point I'm kind of in a routine and don't sweat it.
Enjoy the journey. Cheers.