@octothorpe The vowels aren't the same for me. Both diphthongs, but not the same one. The 'high" vowel in "high" by itself is ah-ee, but in "high school" it's uh-ee, same as in "rice" and "nice" and "splice".
The Cambridge Dictionary does not show a phonetic symbol for my uh-ee diphthong; it has only the ah-ee one, exemplified by "eye", and that's the one it shows for "high", "rice", "nice", and "splice". Wikipedia has a chart giving that same ah-ee diphthong for both "lied" (uses ah-ee in my speech) and "light" (uh-ee in my speech). And the more I look, the more sources I find saying uh-ee is not one of the eight English diphthongs.
I'm not going to start pronouncing "light" as though the vowel were the same as in "pride". It just ain't!