I've got Pi-top Ceed (PTC) without customs today in Slovenia, Europe but seems that has problem showing on screen after RPi3 boots but it boots only powered by micro-USB to USB cable connected on my PC while it doesn't boots by PTC power button. Green and red light are flashing alternately while on hub board green LED powers on after a few seconds like it is in ready mode as it should lit constant. I have tested RPi3 board with USB and HDMI cable on PC screen and boots normal to setup screen.
Connections are all checked that there is no loose cable. It has GPIO 40 pin cable. How I test that PTC screen works? I have connected Pi-Top speaker on hub on right side of board.
I have tested that combination already. I have checked that forum before I have written topic on it. RPi3 works only without hub connected. On PC monitor by HDMI and USB cable. On PTC power on and boots only by micro-USB connected to RPi3 board but there is no screen. Power button on PTC doesn't boot hub to power RPi3 and screen.
I had a similar problem, that was caused by a bad connection on the display connector. You can carefully check the display connection on the hub
No answer after I have send them video of error as they requested. That was a 10 days ago.
I've got replacement hub from them after a while and it worked since then.