PostTickComponentUpdate happens many times and decreases FPS

Could you let me know why the phenomenon below happens ?

  • “ParallerFor”/“PostTickComponentUpdate_ForcedGameThread” of “RecastNavMesh-Default.NavRenderingComp” occurs many times while playing a game.

    • on the first screen shot, whenever the game thread time per tick soars,“ParallerFor”/“PostTickComponentUpdate_ForcedGameThread” of “RecastNavMesh-Default.NavRenderingComp” happens as well.
  • Also the duration for “PostTickComponentUpdate_ForcedGameThread” of
    "RecastNavMesh-Default.NavRenderingComp"is very long.

    • Recreate / AddPrimitive = 6.3ms
    • Recreate / Component UpdateBounds = 4.3 ms
  • Also, this phenomenon does not always happen… it means that when I play a game with Unreal Editor sometimes
    this phenomenon happens and causes its FPS very low while playing the game, but other times this
    phenomenon does not happen and its FPS does not become low during whole playing time.

    • the second screen shot shows a general playing case without “ParallerFor”/“PostTickComponentUpdate_ForcedGameThread” of “RecastNavMesh-Default.NavRenderingComp”
    • I did not change anything before playing each case, but sometimes this phenomenon happens and other times this does not happen…

My game has a NavMesh for some AI-characters and also uses " Navigation Invokers" with the values of “Active Times Update Interval” being 1.

I would like to figure out why this happens irregularly, also to prevent this from happening in order to keep its FPS high.
Could anyone give me an advice or a tip to solve this issue ?

Thank you in advance.