Minecraft Launcher shows that I can only play DEMO, but I've already bought the game

I've bought the game 5 years ago, but after I downloaded the latest launcher this week, it shows that I haven't bought the game before. I'm sure I've already logged in microsoft store and xbox with the same account, and when I click the buy now button, it also says I've already bought the game before. the launcher said "we couldn't connect to the Minecraft Service", no matter how many times I restart, log in and out, or re-download it, the issue is still not fixed. Please help me, thanks.