There seems to be an increase of rate-limited 429 responses from the API endpoints, primarily on these endpoints:

api.minecraftservices.com/minecraft/profile/skins
sessionserver.mojang.com/session/minecraft/profile/:uuid
api.minecraftservices.com/entitlements
api.minecraftservices.com/minecraft/profile
api.minecraftservices.com/authentication/login_with_xbox

This appears to have started on 2024-10-15 around 12:00UTC (see attachment; grouped by 30min).
These are requests made from multiple servers/IPs, which have never had this many requests blocked.

The login_with_xbox endpoint in particular is also causing issues with logins on minecraft.net, which shows "We could not validate your access, please try to login again." as a result.