@EA_Illium Just wanted to pop in to say I am running into this same issue! I own the full version of It Takes Two, and I am attempting to play online with my friend who has the Friend Pass. Every time she attempts to accept my invitation to play, she encounters Result Code: 150-80190000, and is unable to join. To add to this confusion, I have ALSO encountered Result Code: 150-80190000 a handful of times when attempting to begin an onilne game on my Nintendo Switch.
This error has occured over a dozen times for us within the last three days. Every other network function of our Nintendo Switches, such playing other games online, works with no issues. We have both attempted to uninstall and re-install the games, and power cycle our devices, but to no avail. I have a screenshot of the error code, which can be viewed at the following link:
https://imgur.com/a/my2oF0Q 
