Cannot create a realm, despite being able to join servers

So, when I try to create a realms server is tells me that I need permission because of how my account is set up, and I can change it on xbox.com.

Here's the thing that annoys me. I CAN PLAY ON SERVERS AND JOIN OTHER REALMS with no issue, but I cannot create one. Also, in my family, I am an adult account. My Win10 xbox privacy settings are set to allow me to play online, infact, all of those settings are enabled, and always have been. I'm not sure what the issue is. Please help.