diff --git a/PKHeX.Core/Legality/Encounters/Templates/GO/EncounterSlot8GO.cs b/PKHeX.Core/Legality/Encounters/Templates/GO/EncounterSlot8GO.cs
index b39981964..1946240cd 100644
--- a/PKHeX.Core/Legality/Encounters/Templates/GO/EncounterSlot8GO.cs
+++ b/PKHeX.Core/Legality/Encounters/Templates/GO/EncounterSlot8GO.cs
@@ -231,11 +231,15 @@ public sealed record EncounterSlot8GO(int StartDate, int EndDate, ushort Species
             return EncounterMatchRating.PartialMatch;
         if (Species is (int)Farfetchd && IsReallySirfetchd(pk))
             return EncounterMatchRating.DeferredErrors;
+        if (pk is ITeraType ro && IsTeraTypeMismatch(ro.TeraTypeOriginal, PersonalTable.SV[Species, Form]))
+            return EncounterMatchRating.DeferredErrors;
         if (!this.GetIVsValid(pk))
             return EncounterMatchRating.Deferred;
         return EncounterMatchRating.Match;
     }
 
+    private static bool IsTeraTypeMismatch(MoveType original, PersonalInfo9SV pi) => original != TeraTypeUtil.GetTeraTypeImport(pi.Type1, pi.Type2);
+
     /// <summary>
     /// Checks if a Farfetch'd was originally a Sirfetch'd.
     /// </summary>
@@ -250,8 +254,8 @@ public sealed record EncounterSlot8GO(int StartDate, int EndDate, ushort Species
             return false; // can't tell if it was originally Farfetch'd
 
         Span<char> name = stackalloc char[pk.TrashCharCountNickname];
-        pk.LoadString(pk.NicknameTrash, name);
-        return name is "Sirfetch'd"; // only way to get the bad apostrophe is to originate in HOME with it.
+        int length = pk.LoadString(pk.NicknameTrash, name);
+        return name[..length] is "Sirfetch'd"; // only way to get the bad apostrophe is to originate in HOME with it.
     }
 
     public byte OriginalTrainerFriendship => Species switch