Well sure, but from what I’ve heard (as in actual Japanese, not from someone else) people tend to speak Japanese so fast some of the sounds get blurred together. It’s possible some of those sounds in the words are ‘official’, it’s just that you don’t really hear it when fluent people actually say it to you.
Or I’m just making all this up, cuz I have no clue what any of those word’s meanings are. (poor level 2 lol)
I used to think that some words didn’t “sound Japanese” early on when I was learning, but that was just because I had such a limited knowledge that I didn’t actually know what Japanese sounded like. (When I first started out, I used to think words like ぶどう, the word for grape, didn’t sound “cool enough” to be Japanese.) I’d only heard a very small sample of the language, and only from anime which gave me a skewed impression. I think as you come to listen to more and more of the language, you’ll get a better idea of what it actually sounds like. That’s what happened with me at least. I thought 発表 sounded a little funny when I first learned it on Wanikani, but it no longer sounds out of place now that I have a (somewhat) larger vocabulary.
I remember when I encountered the vocabulary word 部分 and I thought, “That can’t possibly be pronounced ぶぶん can it? That doesn’t sound like Japanese!” But sure enough, it was. Keep your mind open.
In the weather report I often heard something that sounded like 「おがさわらショット」 and I kept wondering what this “Nantoka Shot” could be (but never wondering enough to actually look it up).
Finally WK came around the corner on level 52 and taught that the onyomi of 島 is とう. So in the end it was 諸島 (しょとう), a group of islands.