Only run the fix-up tasks once.

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -266,9 +266,11 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
       data = data
       |> Map.put(:info, Map.merge(user.info, data[:info]))
 
+      already_ap = User.ap_enabled?(user)
       {:ok, user} = User.upgrade_changeset(user, data)
       |> Repo.update()
 
+      if !already_ap do
         # This could potentially take a long time, do it in the background
         if async do
           Task.start(fn ->
@@ -277,6 +279,7 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier do
         else
           user_upgrade_task(user)
         end
+      end
 
       {:ok, user}
     else