This issue seems to crop up for me after playing 1+ games, it only started happening to me I believe when Graves was added. Deadlock worked perfectly before then.
I have the same issue after playing more than one game, the stutter is exactly like the ones that happen when preloading shaders on game launch.
I posted another topic with my console output during one of the stutters, not sure if it's actually relevant
[Client]...
This started sometime in the patch that Graves was added.
During my first game of the day everything works fine, but some time into the second game, I will start getting intermittent stuttering that acts exactly like the stuttering that happens when first launching the game and it's preloading...