Realms do not appear (currently paying for a Realms Plus monthly subscription)
Marketplace is not available (see screenshot attached)
This issue has been happening for a few months now. Prior attempts to reach out to support have not been successful. Suggested fixes that have been tried include:
Rebooting the Xbox
Reinstalling Minecraft
Switch from Wifi to Wired (has always been wired)
Set NAT type to "Open" (has always been "Open")
Duplicate of MCPE-155025.