- Star Trek: The Next Generation S6E9 “The Quality of Life”
- https://knowyourmeme.com/memes/drakeposting
- https://memory-alpha.fandom.com/wiki/Kelvin
- https://en.wikipedia.org/wiki/Kelvin
According to SI convention, the kelvin is never referred to nor written as a degree. The word “kelvin” is not capitalized when used as a unit. It may be in plural form as appropriate (for example, “it is 283 kelvins outside”, as for “it is 50 degrees Fahrenheit” and “10 degrees Celsius”).[5][63][64][65] The unit’s symbol K is a capital letter,[39] per the SI convention to capitalize symbols of units derived from the name of a person.[66] It is common convention to capitalize Kelvin when referring to Lord Kelvin[5] or the Kelvin scale.[67]


I was taught as degrees Kelvin in middle school, (as well as degrees Rankini). Only in high school it was changed. Not sure if it was a change in standard or a correction in teaching.
According to Wikipedia it was officially changed from “degrees Kelvin” to “kelvins” in 1967, so it’s possible you were seeing the change ripple out as they were made. I wonder how long it takes for decisions like that to get from a decision announcement from the CGPM to an update in textbooks that students use. Probably varies by income level.
I’m sure the changes must be ratified at country level, which adds another significant layer of delay.