Hey
How about a second “like” button, but stating that this reply is the correct solution to the problem of the given topic. Kinda like the “correct answer”-marking on stack overflow. The post with the most “correct-votes” or that is marked as best answer by the topic author gets highlighted and could be pinned under the opening post. This way you could give feedback to the topic author without posting a reply “xyz’s answer is the best/correct solution for your problem”. In addition, people with the same or similar problems could find a solution quickly instead of searching through a lot of replies
Greetings
- Phil