What is the screw type, size, and length of the four screws that hold the case together? I find they are too short! I barely got one thread turn in gauged on three screws and could not get the 4th screwed in at all! I am using the four longest screw, not the 2 shorter ones for the case top. Also, it would be nice if the PCIE flat flex cable could be a little longer. I had a difficult time getting it in the NVME carrier board.
Same here, I’ve raised a support request so they can send me longer screw types, my pi is just rocking around in the box because of that, and when i insert a usb drive, it turns off the system 
Just want to reiterate this issue.
Bought two Neo NVMe cases and the screws are indeed too short. Luckily my box of spares had some M2.5 x 8 screws in which work perfectly. Supplied are M2.5 x 6 and are inadequate.
I found on my NEO the four flat-head screws were for the M.2 heat sink and the four round-head screws were for the case bottom. Make sure you haven’t gotten them reversed.
They are not reversed on my NEO. The round head screws are too short.
I have a similar issue - I cannot get thw two screws on the hdmi and usb-c side to secure. They keep on falling out. The other side secured, but I don’t know by how much.
All 4 screws are the same length.
Screws are definitely too short on one side. It seems slightly longer screws should work as the current ones just about touch the thread. Would only replace them in the side where you can see the top screw hole.