Quick answer: Cross-team bugs (touching two systems) often sit untouched because of ownership ambiguity. A 'driver' pattern (one team owns the bug; others provide help) breaks the impasse.
Bugs that touch multiple teams are the longest-lived. Ownership ambiguity is the bug; not the code.
Assign one driver team
Most-affected team drives. Other teams provide support without ownership.
Standing cross-team meeting
Weekly; 30 minutes; discuss cross-team bugs. Resolution paths surfaced; ownership clarified.
Define escalation
Cross-team bug sat for 2 weeks. Escalate to engineering lead. Lead picks the driver.
Track separately
Cross-team tag in the tracker. Separately visible; doesn't disappear into per-team queues.
“Cross-team bugs are organizational, not technical.”
If your studio has 3+ teams, cross-team bug handling deserves an explicit process. Otherwise the bugs accumulate.