failed to connect to host error

Hello Adan, this is Manuela. I'm an Independent Advisor and community user like you, ready to assist with this.
Not a Microsoft employee.

I understand you’re having some trouble when trying to play Astroneer with your friend. Let’s try to sort this out.

However, before that, I would like to ask the following questions:

Is this the only game affected when you try to play with your friend?
Are you able to play this game with a different friend, or do you experience the same inconvenience with another friend?
What procedures you tried to fix this prior to your post creation?

Lastly, what’s appearing in the NAT type field?
You can review this by installing and opening the Xbox Console Companion app > Settings > Network.

Please ask your friend to verify their NAT type as well.

Going back to the connection issue. I hate when I play blops and I'm doing good when I get the connection to host failed error and I'm sitting back in the lobby, game counting down for a new map.....so mad.

Haha so true. I have constant lost connection to host fails. :/

lost connection could be due to:

dash boarders

host quits

failed lag switch

restricted nat

connection drop

Hi Zenuon
Can you and your friend try to close and re-open the NAT ports in the router?

Let me give you the ports:

Port 88 (UDP)
Port 3074 (UDP and TCP)
Port 53 (UDP and TCP)
Port 80 (TCP)
Port 500 (UDP)
Port 3544 (UDP)
Port 4500 (UDP)

Make sure to contact your Internet Service Provider for this.