There is an issue with enemies returning when ruins disappear.
This problem occurs when a ruin disappears from the map. such as when I leave it, or when its value is reduced to 0.
Human raids are no big deal, but Mechanoid raids or Mechanoid clusters will remain on the map.

there are error log
Error while sending signal to RimWorld.Quest: System.NullReferenceException: Object reference not set to an instance of an object
at RimWorld.Quest.Notify_SignalReceived (RimWorld.Signal signal) [0x00020] in <95de19971c5d40878d8742747904cdcd>:0
at RimWorld.SignalManager.SendSignal (RimWorld.Signal signal) [0x000b6] in <95de19971c5d40878d8742747904cdcd>:0
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
RimWorld.SignalManager:SendSignal (RimWorld.Signal)
RealRuins.RuinedBaseComp:CompTick ()
RimWorld.Planet.WorldObject:Tick ()
RimWorld.Planet.MapParent:Tick ()
RimWorld.Planet.WorldObjectsHolder:WorldObjectsHolderTick ()
RimWorld.Planet.World:WorldTick ()
(wrapper dynamic-method) Verse.TickManager:Verse.TickManager.DoSingleTick_Patch1 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
(wrapper dynamic-method) Verse.Game:Verse.Game.UpdatePlay_Patch1 (Verse.Game)
Verse.Root_Play:Update ()

there are mod list
- harmony
- RimWorld
- Royalty
- Ideology
- Biotech
- HugsLib
- EdBPrepareCarefully
- MapReroll
- MoreFactionInteraction
- RealRuins
- RKTM.Mod
- smartspeed
- RocketMan
- ModManager