I have the exact same problem reported by dozens of players saying that after some time playing the game keeps stuttering every 5s-10s making it impossible to play. The only solution is killing the game and starting over but it doesn’t solve the problem.
Check my linked post below where I show I capture of this with a very low latency network.https://us.forums.blizzard.com/en/d4/t/stuttering-problem-video-evidence-with-low-ping-and-system-info-june-2023/31191