Account-specific matchmaking issue - unable to find matches

Hello, I am experiencing an account-specific matchmaking issue in Overwatch 2 on PC. My main account cannot find Quick Play or Competitive matches, even after 10+ minutes in queue. I tested this with a friend: my friend finds a match immediately when playing alone, but when my main account joins the group, the group cannot find a match, even when my friend is the group leader. I created a new Blizzard account for Overwatch and tested it on the exact same PC, Windows installation, Ethernet connection, router, and STC internet connection. The new account successfully found and entered a match normally. Practice Range works on my main account, and the connection is stable. The issue started suddenly, temporarily disappeared yesterday, and returned today. These comparisons suggest an account-specific matchmaking issue. Please investigate my main account's account-side matchmaking/backend state and check whether any restriction, stuck session, or matchmaking flag could be preventing it from finding matches. Thank you.