Please report it. To appreciate means "vážit si + genitive"; to respect means "respektovat + accusative". They are very close in the meaning and often interchangeable, but for example when your boss is an ❤❤❤❤❤❤❤, you still respect him (respektovat), but never appreciate him (vážit si).
"Vážit si" has several meanings, two of which are "to respect" and "to appreciate" (https://glosbe.com/cs/en/v%C3%A1%C5%BEit%20si), both of which have been used in the course.
Absent context, it seems to me that "appreciate" should be acceptable here. If you see this again, you could report it as "My answer should be accepted," if that option is available (at the moment, though, it's not there...)
UPDATE = = = = =
"Is he starting to appreciate me?" was just accepted for me...