The Cryotra beam has been bugged for a little while now, it will appear for 1-2 frames then detach, become invisible then just spawn particles from the point it began firing. This does not happen with Artax, a very similar weapon. This second one is whenever the sentinel targets a Kuva Siphon, it will repeatedly try to shoot and stop shooting, spawning vast numbers of particles and audio spam. This happens with other enemies, like the Bounty on Orb Valis that makes you defend the Coil Drive, but the Kuva Siphon it happens 100% of the time. To my knowledge, this does not happen with the OLDER targeting mods like Striker, it only began with Assault Mode.