Hi there, and thank you for reaching out -- I completely understand your frustration. You've clearly put in serious effort troubleshooting, and it's genuinely disappointing when you've invested in all the pieces (Switch 2, online subscription, the game itself) only to hit a wall.
Error 105-80190000 on the Nintendo Switch can be tricky, especially when you've already tried the standard troubleshooting steps. Here are a few other things worth trying:
Try these:
Make sure your Switch 2's system time is set to synchronise automatically via the internet -- sometimes account issues get finicky when time sync is off.
If you're both on the same WiFi network, try connecting over a different network, if possible (such as a mobile hotspot or a friend's WiFi), just to rule out any router-level issues.
Try a hard restart of your Switch by holding the power button for 12 seconds or more to fully power it down, then turn it back on and attempt to connect again.
If those don't work:
Reach out to our EA Support team at https://help.ea.com. You can submit a ticket with your Nintendo ID and this error code, and they can review your specific account setup to determine if there's anything that needs checking.
Really sorry you're dealing with this. Hopefully, one of these steps will help you get back in the game with your husband!