Quick answer: Unreal Blueprint AddComponent in Construction Script not persisting after compile? Construction Script runs on edit; components transient unless created with proper flags.
Spawn a procedural mesh component in construction; compile; component disappears.
Use SetMobility and CreateObject
AddComponent's persisted-flag variant. Explicit; survives compile.
Or add in BeginPlay
Runtime add; per-instance. Doesn't try to live across compile.
Audit Construction Script
Construction Script is editor-time. Runtime state belongs elsewhere.
“Construction Script is for editor-time. Runtime-style adds don't fit.”
If your BP relies on Construction Script adds, refactor to BeginPlay or use proper persisted-flag variants.