Following the upper enemy marker revealed that the Siphon's pipe is pointing at the wrong direction
A better picture: here, you can see that the SIphon's pipe is pointing to the left, while the Kuva itself is coming from the back.
I thought that it might be a Solo problem, so I tried using different variations of weapons and frames to multiple Kuva missions. A clanmate ran group missions and noticed the same problem.
Thank you in advance.