@AxeBurningfire i know you posted that comment MONTHS ago but im posting anyways.
so the 'tsu' character has two functions:
when normal sized, such as with なつき, it's read as 'tsu'. so Natsuki.
but when smaller sized, as in なっき, it functions as a kind of double consonant. so Nakki.
without the little tsu, ちょっと まって wouldn't be "chotto matte", it would be "cho to mate". and if the little tsu were misread as a big tsu, it would be "chotsuto matsute"
its easy for machine translations to pick up a little tsu as a big tsu, but i dont think ive ever seen a machine translation mistake a big one for a little one, so i'm assuming its TL error. which you probably already knew, but now you know why!