After contacting Elektron support, they said that a factory reset won’t solve this problem. I think you’re good to send the unit back to Sweden!
Hopefully don’t take long to fix
If I had to guess, I would say this issue is somehow related to bad flash memory used either by the processor or the FPGA. It could be returning the wrong data depending on some other factor, like device temperature, thus raising an exception. Maybe different OS versions place the code in slightly different places, causing the issue to manifest. In order words, it is likely a HW fault. It would be interesting to try to determine if all affected units were manufactured at the same period.