Hope you get them sorted.
As a few people have said, the ‘problem’ is that the mounting holes in the sides of the Elektron cases perfectly line up with the control PCB that is mounted to the underside of the top panel. This is true of all Elektron machines.
I measured the inside of the cases and there is just about 5mm of space between the inside edge of the enclosure and the edge of the PCB.
When I supply mounting screws with my acrylic stands I only send 6mm screws with stands made from 3mm acrylic and 8mm screws with 5mm stands. This means that only 3mm of the screw actually penetrates the enclosure.