I just looked at amazon jp and everything that I had in my cart shows not in stock, even newly released magazines and books, it shows private sellers which don't ship to the U.S. I don't know if they changed their policy or this is temporary, has anyone else had this issue

Probably a (temporary) sweeping change to not ship them internationally (you can verify by changing your address to a Japanese one).

It has happened before for various categories of goods, at least.

I haven't tried changing address but even the section that shows top anime items bought from international customers are unavailable which they always have in stock. I was only able to find 1 azur lane figure that's shipped and sold by Amazon. It just seems weird how long they just did this compared to the other times they did it to only few categories or was available but will show a message that it can't ship internationaly

It's a conspiracy I tell you! Jeff Bezos has decided to make us all writhe in pain for his latest amusement!