First of all, I removed the KS from your post, you should never share that since it would allow anyone to use it while it’s valid [by default, a KS is valid for 24 hours or 86400 seconds].
As for your question, do you actually see playlists in the KMC for the partner this KS belongs to?
If you connect your iOS device to a laptop and run a sniffer, you should be able to see the exact api_v3/index.php?service=playlist&action=list HTTP request being made to our endpoint, which should include the KS, that KS can also be decoded so you can see its attributes.