Epic Marks Unreal Engine 5.8 Garbage Collection Regression Fixed for 5.8.5

A performance regression affecting garbage collection in Unreal Engine 5.8 has received an important status update. On November 4, 2026, the official Bug-Reporter account on Epic's forums marked issue UE-398681 closed as fixed and said the change would be addressed in Unreal Engine 5.8.5. That means a fix is planned for an upcoming hotfix, not that every installed 5.8 build already contains it.

The original report was opened in August after a developer compared Unreal Engine 5.7.2 with 5.8.1. In a deliberately simple project, the author spawned a large number of actors and triggered level teardown while profiling garbage collection. The reported Purge Garbage phase took at least ten times as long in the newer engine version. Additional forum participants described their own longer unload times. These are user-provided measurements rather than a universal benchmark across games.

The report is particularly relevant to projects that create and remove many transient actors. Examples include games with numerous enemy units, projectiles, temporary physics objects or large levels that need to unload quickly. A stall during a world transition may be less noticeable when hidden by a loading screen, but long pauses still harm responsiveness and can complicate production testing.

The original author shared reproduction projects and Epic requested further material to investigate the issue. That sequence matters: the confirmed status change follows an identifiable bug report and reproduction effort, rather than an unverified suggestion on a forum. Nevertheless, the public thread does not provide a detailed explanation of the underlying code change or evidence that every garbage collection performance issue in 5.8 has the same cause.

Developers can prepare a controlled benchmark now. In separate copies of a project, record the time required to spawn a known number of representative objects, transition levels and complete garbage collection. Use Unreal Insights or equivalent engine profiling information, and repeat the test in a packaged build where practical. Keep hardware, project settings and object counts constant.

When 5.8.5 becomes available, rerun the same workload before migrating the main production branch. Compare worst-case frame stalls as well as averages. Any improvement should be measured against the project's own baseline, not inferred from a forum label.

For now the accurate headline is that Epic has confirmed a future fix for a documented regression. The November 4 status update is new; a released 5.8.5 hotfix should be verified separately when it arrives.