So far I assumed a client would just search for peers in the dht and use bep 9 in order to get the metadata, however when trying it myself and opening Wireshark I couldn't find any usage of bep 9. Does the client automatically try trackers or something similar with the Infohash? Or is there something else you can do in the dht with only an infohash to get the metadata without bep 9?
The DHT does not store the torrent metadata, it provides contacts to peers (via get peers) from which you can then download the metadata via the peer protocol and the extensions described in BEP 9.
There also are some websites that store torrents under a path based on their infohash, a client might also try one of those to fetch it.