I have had Minecraft for Many years. I own Java, and two bedrock versions. One bedrock version I originally purchased for my phone. My Java version as well as the Bedrock version I use on my phone (also linked to my PS4 account) has been able to claim the cape fine. However, my Win 10 version (which was free way back when I got Java) cannot claim the anniversary cape (I was able to claim the Twitch cape for) keeps redirecting me to the "I need an account" even though I can login to minecraft.net fine and shows my character name. Obviously I know how to claim the cape since I have done it on two accounts already. I have logged out of all accounts and tried it as well as trying on three different browsers. If needed I can provide user accounts for all 3 if requested.