Probably, you haven't been "penalised". You were on an alternative solution not included yet in the database. Nobody said that you couldn't put the adjective (adverb?) next to the verb.
What was your sentence? I don't see the adverb or any adjective at the end in the suggested correction.
It's an adverb of manner.
You have several choices for the place, it depends whether you want to emphasize it.
The weasel rapidly climbs the tree.
The weasel climbs the tree rapidly.