Was playing the assassination mission as a bounty for the Cavia, when suddenly all weapons just stopped dealing direct damage. I was at my second Vitreum activated when it started happening.
I was running the mission solo, with Revenant Prime, while using Kuva Bramma, Tenet Diplos and Quassus, At some point I could deal damages only through the AoE of the Bramma.
Later in that same mission I tried to take on the Void Angel, and that has been when I noticed that this bug affected also the direct damage of the Amps.
At that point I couldn't progress anymore with the mission and had to abort; being unable to defeat the already awakened Void Angel, the game also didn't allow me to start the actual mission objective.