fix: Prediction.CorrectHistory now adjusts afterIndex after removals/…

…insertions

Assets/Mirror/Core/Prediction/Prediction.cs

@@ -106,17 +106,21 @@ public static class Prediction
             T corrected,     // corrected state with timestamp
             T before,        // state in history before the correction
             T after,         // state in history after the correction
-            int afterIndex) // index of the 'after' value so we don't need to find it again here
+            int afterIndex)  // index of the 'after' value so we don't need to find it again here
             where T: PredictedState
         {
             // respect the limit
             // TODO unit test to check if it respects max size
             if (history.Count >= stateHistoryLimit)
+            {
                 history.RemoveAt(0);
+                afterIndex -= 1; // we removed the first value so all indices are off by one now
+            }
 
             // insert the corrected state into the history, or overwrite if already exists
             // SortedList insertions are O(N)!
             history[corrected.timestamp] = corrected;
+            afterIndex += 1; // we inserted the corrected value before the previous index
 
             // the entry behind the inserted one still has the delta from (before, after).
             // we need to correct it to (corrected, after).