Quick answer: Unreal Iris frequency tuning leaving certain actors un-replicated for visible periods? Iris budgets per-frame bandwidth; low-priority actors get postponed when the budget is full.
On busy frames, distant enemies update only every 5-10 frames. Iris is throttling them under bandwidth pressure.
Net Update Frequency
Per-actor NetUpdateFrequency sets a hint — actors closer to it relative to budget get updates more often. Raise for must-update actors.
Priority Categories
Iris supports priority categories. Tier-1 (player, projectiles) always updates; Tier-3 (decorations) less often. Categorize actors by gameplay importance.
Bandwidth Profile
Check the bandwidth used per second. If you’re hitting your NetServerMaxTickRate ceiling, the throttle is per-design. Either raise the ceiling or trim what replicates.
Insights NetTrace
Run with -trace=net. The trace shows per-actor send latency. Find the actors with high delay; either raise their priority or accept the stagger.
Verifying
Critical actors update at the expected frequency. Distant low-priority actors update less often but consistently — no random stalls.
“Iris is budget-driven. Priority + frequency tier put bandwidth where it matters.”
Categorize actors into priority tiers as part of design — ad-hoc tuning per actor doesn’t scale.