Have you tried hooking up the Xbox to a hardwire connection and downloading the Worlds like that? I'm not saying it could solve it, but it may push the download through with hardwire. If not we may want to bug report this. ^TK
Have you tried downloading the launcher directly from the website and not the Microsoft Store as of yet? If not, I would start there. msft.it/6015bl7VU ^TK
Videos don't assist with verifying ownership. You'll need to submit that ticket and send as much information as you remember. We'll do our best to assist from there. ^TK
Some connection tips can be found by going here. Hopefully this helps some! ://help.minecraft.net/hc/en-us/articles/360055710592-Minecraft-Realms-and-Multiplayer-Troubleshooting ^AC
That's usually indicative of a connection error. Have you tried any connection troubleshooting steps? ://help.minecraft.net/hc/en-us/articles/360055710592-Minecraft-Realms-and-Multiplayer-Troubleshooting ^AC