Fix apply only forced changes

dot/sync/block_importer.go

@@ -117,21 +117,24 @@ func (b *blockImporter) checkAndApplyForcedAuthChanges(blockData types.BlockData
 
 	for i := range consensusDigests {
 		digest := consensusDigests[i]
-		switch digest.ConsensusEngineID {
-		case types.GrandpaEngineID:
+		if digest.ConsensusEngineID == types.GrandpaEngineID {
 			data := types.NewGrandpaConsensusDigest()
 			err := scale.Unmarshal(digest.Data, &data)
 			if err != nil {
 				return fmt.Errorf("unmarshaling grandpa consensus digest: %w", err)
 			}
 
-			err = b.grandpaState.HandleGRANDPADigest(header, data)
+			digestValue, err := data.Value()
 			if err != nil {
-				return fmt.Errorf("handling grandpa digest: %w", err)
+				return fmt.Errorf("getting digest value: %w", err)
+			}
+
+			if _, ok := digestValue.(types.GrandpaForcedChange); ok {
+				err = b.grandpaState.HandleGRANDPADigest(header, data)
+				if err != nil {
+					return fmt.Errorf("handling grandpa digest: %w", err)
+				}
 			}
-		default:
-			// Will be handle by the block importer
-			continue
 		}
 	}