chromeos_strings.grdp has correct spelling.
For some reason components/strings/components_strings_en-GB.xtb has incorrect spelling, but that is the artifact of localization.

British spell Enrollment with just one L. If you're using a british locale, then you should indeed be seeing "Enrolment" (https://writingexplained.org/enrolment-vs-enrollment-difference)

Ok. My bad. It turns out the device my tester showed me was set for British
English.