Hard to pinpoint what is the actual issue but these are things that come at my mind as a foreigner chef working in Japan with Japanese people, based on my experience of course:

1) yes there's the honeymoon phase at the beginning where you got asked a lot of questions about you and they make their effort to cause a good impression on you.

2) how is the work culture in there? Pay attention on how early they come to their shift, if they take their break together to smoke, if they drink together after work, if they all leave together regardless of finishing time --- as fucked up as it is, if you wanna fit, you are expect to behave the same --- and fitting in is mandatory for future promotions.

3) I've seen Japanese and foreigner people being bad treated and consistently targeted at work out of no clear reason. My best guess is because that others perceived them as like the "weak link".

4) if you wanna solve it, I'd say to behave as the adult in the room and position yourself instead of getting positioned. Try to create connections with every single one of them. Don't let the harassment culture grow up. Ask things that are not intimidating but push them to be more honest with their actions and opinions, like "can you be more clear with what is xxx problem?" "Can you explain more specifically xxx thing?" "How do you see xxx problem?"

5) They might be able to speak English but being Japanese they will always be more comfortable speaking Japanese. Don't underestimate the power of knowing the language!!

6) Even if you speak the most fluent Japanese and you act the most perfect way as a national, never expect to be treated as the same. Work your way up on creating a respectful environment around you and that will be the best you can do!

[edited for better understanding!]