I just had a frustrating interaction on this topic:
The answer I gave is the ば conjugation of the prompted verb (this conjugation is listed in the lesson as an option). I believe that at worst it should be a “soft fail”. If I instead answer with 会えばいい (the ば conjugation of the base form of the prompted verb), I’m indeed given the soft fail, i.e. “let’s try … a stronger nuance”.
It’s easy for me to undo this and keep the grade, but I don’t at all understand the gold error text in this image (presumably it’s referring to this lesson I have not yet reached. As I understand it, the answer I gave means the correct thing, just not with a strong enough nuance.