My roommate and I have not been able to join each other in Minecraft Dungeons on our Nintendo Switches. It has been roughly a week without ever successfully joining each other. 

When I attempt to join my roommate, it loads for a couple minutes, then I get the error message: 

CONNECTION TIMEOUT - The connection to the host timed out.

When he attempts to join me, it loads for ONLY a few seconds before getting the error message: 

JOIN SESSION FAILURE - Sorry, the Minecraft Dungeons service is not currently available. Please try again later.

We receive those exact messages every time. So, I have not received the JOIN SESSION FAILURE, and he has not received the CONNECTION TIMEOUT. 

Troubleshooting methods we've attempted: 

1. Signing out of Microsoft accounts and re-logging in. We've even signed in with multiple different Microsoft accounts. This did nothing for us. 
2. Changing our IP address and DNS from "Automatic" to "Manual" in our WiFi settings of our Switches, with new IP address for our devices to avoid getting the same IP addresses, but this did nothing. 
3. We've called our service provider and they've assured there's nothing wrong on their end that would be causing this issue. 
4. We've made sure our Microsoft account settings are "Open" with no restrictions of any kind, including the Parental settings. 
5. We've tried joining each other using Hot Spots from different cellular devices to avoid any conflictions using the same WiFi. Even being on completely different internet connections, we still get the same messages. 
6. Uninstalled and reinstalled our Minecraft Dungeons. 

Also worth noting, we have the Xbox versions as well, and can join each other no problem on there. Nintendo Switch seems to have the only issue. 

I'm running out of ideas and would hope I could speak with someone if possible, would probably be easiest to cover any specifics on our attempts to troubleshoot