Well don't have time to post details, will do this evening, but I listened to a song from a soundtrack on an album which was different than the EP version or the Youtube performance version. The album (on Apple music) used autotune on this particular song, noticeable on one word especially. Well I think it's the case.
Well better late than never. So this song from the "Solo Leveling" anime soundtrack by a Hiroyuki Sawano (famous in anime circles) the singer has a lovely voice and does a good job but has an accent noticeable on one word. Here is the performance version:
Here is the album (it's the first track) from Apple music which sounds re-recored or reworked? The word in particular being "similarities"
Not criticizing as her voice is better in a foreign language than me in English.
Josphine Baker sang in French with an American accent after all.
Banger soundtrack as is all Sowano's work, most famously in Attack on Titan, his student Kohta Yamamoto took over for the final season of AoT.