I got Sword, he got Shield.
We are sitting next to ech other on same couch, connected to same WiFi.
We got online subscriptions active.
Dynamax fight works both in Local Connection and in Internet mode. We can join each other without problems.
Random people from other side of globe can join our trades.
We see each other trade broadcasts.
And yet, we can't trade with each other. "Link Trade" button is grayed out.
How in tarnation are we supposed to trade?
Best Answer
It appears trade invites works differently from Dynamax raid invites. While you actively join Dynamax teams, for trade you both of you have to broadcast invitation and then wait for game to match you.
I got it to work in Internet mode on same WiFi, successfully traded between Sword and Shield versions.
If you still have trouble with connecting, eg. not seeing invites or getting error while joining Dynamax team: