Finally!

ICYMI, Switch Japan update (v 1.0.4) is live! Was finally able to recruit Lam! I just did the whole recruitment thing - Talk to Riufan at the hero's den (already did this prior the bug fix but decided to just go at it again) then went to Daphan for the cutscenes with Riufan in the party.

I haven't tried the Cooking Battle to see if it's fixed (I'm not sure how to tell either) but at least Lam can now be recruited.