the system locale isn’t automatically set to en_US.UTF_8. This causes some applications to break/not launch, and I had to manually set it. this is probably caused by the OEM install, even though I set the language to American English.
system locale - for a live ISO - is initially set by the selection made in grub.
Some of these will be used by the Calamares installer and is preselected on the language selection screen.
As such the system locale will be set to what ever you choose - anything else would cause a stir.