The problem was solved in November.
Hello, the logs have been uploaded.
I had the same problem, I wrote to support and according to their instructions that I tried a bunch of methods to solve the problem: I activated it from my phone, browsers, from Linux and Windows (new on a virtual machine) on each of these steps I tried vpn. Support said that with error 403 (Access to fetch at 'https://api.minecraftservices.com/minecraft/profile' from origin 'https://www.minecraft.net' has been blocked by CORS policy: No ' Access-Control-Allow-Origin' header is present on the requested resource.
FetchHttpClient.ts:70
POST https://api.minecraftservices.com/minecraft/profile net::ERR_FAILED 403) they can't do anything, contact your ISP. He tried changing the default IP and settings, but that didn't help either. And they can't help anymore. After I wrote about it to minecraft support they told me to write about it on the bug tracker and hope that the developers will fix it someday.
Sorry, after reinstalling the fabric, the problem was fixed.