diff --git a/src/emqx_message.erl b/src/emqx_message.erl
index 7e78a3dac..23ddd69d4 100644
--- a/src/emqx_message.erl
+++ b/src/emqx_message.erl
@@ -57,8 +57,6 @@
 
 -export([ to_map/1
         , to_list/1
-        , to_bin_key_map/1
-        , to_bin_key_list/1
         ]).
 
 -export([format/1]).
@@ -193,24 +191,11 @@ update_expiry(Msg) -> Msg.
 to_map(Msg) ->
     maps:from_list(to_list(Msg)).
 
-%% @doc Message to map
--spec(to_bin_key_map(emqx_types:message()) -> #{binary() => any()}).
-to_bin_key_map(Msg) ->
-    maps:from_list(to_bin_key_list(Msg)).
-
 %% @doc Message to tuple list
 -spec(to_list(emqx_types:message()) -> map()).
 to_list(Msg) ->
     lists:zip(record_info(fields, message), tl(tuple_to_list(Msg))).
 
-%% @doc Message to tuple list
--spec(to_bin_key_list(emqx_types:message()) -> map()).
-to_bin_key_list(Msg) ->
-    lists:zipwith(
-        fun(Key, Val) ->
-            {bin(Key), bin_key_map(Val)}
-        end, record_info(fields, message), tl(tuple_to_list(Msg))).
-
 %% MilliSeconds
 elapsed(Since) ->
     max(0, timer:now_diff(os:timestamp(), Since) div 1000).
@@ -225,15 +210,3 @@ format(flags, Flags) ->
     io_lib:format("~p", [[Flag || {Flag, true} <- maps:to_list(Flags)]]);
 format(headers, Headers) ->
     io_lib:format("~p", [Headers]).
-
-bin_key_map(Map) when is_map(Map) ->
-    maps:fold(fun(Key, Val, Acc) ->
-                      Acc#{bin(Key) => bin_key_map(Val)}
-              end, #{}, Map);
-bin_key_map(Data) ->
-    Data.
-
-bin(Bin) when is_binary(Bin) -> Bin;
-bin(Atom) when is_atom(Atom) -> list_to_binary(atom_to_list(Atom));
-bin(Str) when is_list(Str) -> list_to_binary(Str).
-
diff --git a/src/emqx_mqueue.erl b/src/emqx_mqueue.erl
index 594599daf..f13ccdd34 100644
--- a/src/emqx_mqueue.erl
+++ b/src/emqx_mqueue.erl
@@ -124,8 +124,8 @@ stats(#mqueue{max_len = MaxLen, dropped = Dropped} = MQ) ->
 
 %% @doc Enqueue a message.
 -spec(in(message(), mqueue()) -> {maybe(message()), mqueue()}).
-in(#message{qos = ?QOS_0}, MQ = #mqueue{store_qos0 = false}) ->
-    {_Dropped = undefined, MQ};
+in(Msg = #message{qos = ?QOS_0}, MQ = #mqueue{store_qos0 = false}) ->
+    {_Dropped = Msg, MQ};
 in(Msg = #message{topic = Topic}, MQ = #mqueue{default_p = Dp,
                                                p_table = PTab,
                                                q = Q,
diff --git a/src/emqx_plugins.erl b/src/emqx_plugins.erl
index ee12ed96a..af7a32f9a 100644
--- a/src/emqx_plugins.erl
+++ b/src/emqx_plugins.erl
@@ -276,7 +276,11 @@ plugin_unloaded(_Name, false) ->
     ok;
 plugin_unloaded(Name, true) ->
     case read_loaded() of
-        {ok, Names} ->
+        {ok, Names0} ->
+            Names = lists:filtermap(fun(Name1) when is_atom(Name1) -> {true, Name1};
+                                       ({Name1, true}) -> {true, Name1};
+                                       ({_Name1, false}) -> false
+                                    end, Names0),
             case lists:member(Name, Names) of
                 true ->
                     write_loaded(lists:delete(Name, Names));
@@ -306,4 +310,3 @@ write_loaded(AppNames) ->
             ?LOG(error, "[Plugins] Open File ~p Error: ~p", [File, Error]),
             {error, Error}
     end.
-
diff --git a/src/emqx_session.erl b/src/emqx_session.erl
index 3ef9107a7..2ef64c9aa 100644
--- a/src/emqx_session.erl
+++ b/src/emqx_session.erl
@@ -812,7 +812,11 @@ is_awaiting_full(#state{awaiting_rel = AwaitingRel,
 %% Dispatch messages
 %%------------------------------------------------------------------------------
 
-handle_dispatch(Msgs, State = #state{inflight = Inflight, subscriptions = SubMap}) ->
+handle_dispatch(Msgs, State = #state{inflight = Inflight,
+                                     client_id = ClientId,
+                                     username = Username,
+                                     subscriptions = SubMap}) ->
+    SessProps = #{client_id => ClientId, username => Username},
     %% Drain the mailbox and batch deliver
     Msgs1 = drain_m(batch_n(Inflight), Msgs),
     %% Ack the messages for shared subscription
@@ -823,7 +827,9 @@ handle_dispatch(Msgs, State = #state{inflight = Inflight, subscriptions = SubMap
                       SubOpts = find_subopts(Topic, SubMap),
                       case process_subopts(SubOpts, Msg, State) of
                           {ok, Msg1} -> [Msg1|Acc];
-                          ignore -> Acc
+                          ignore ->
+                              emqx_hooks:run('message.dropped', [SessProps, Msg]),
+                              Acc
                       end
               end, [], Msgs2),
     NState = batch_process(Msgs3, State),
@@ -957,7 +963,7 @@ enqueue_msg(Msg, State = #state{mqueue = Q, client_id = ClientId, username = Use
     if
         Dropped =/= undefined ->
             SessProps = #{client_id => ClientId, username => Username},
-            ok = emqx_hooks:run('message.dropped', [SessProps, Msg]);
+            ok = emqx_hooks:run('message.dropped', [SessProps, Dropped]);
         true -> ok
     end,
     State#state{mqueue = NewQ}.
diff --git a/test/emqx_bridge_SUITE.erl b/test/emqx_bridge_SUITE.erl
index 238871d05..b33a64210 100644
--- a/test/emqx_bridge_SUITE.erl
+++ b/test/emqx_bridge_SUITE.erl
@@ -87,6 +87,7 @@ t_rpc(Config) when is_list(Config) ->
         %% message from a different client, to avoid getting terminated by no-local
         Msg1 = emqx_message:make(<<"ClientId-2">>, ?QOS_2, <<"t_rpc/one">>, <<"hello">>),
         ok = emqx_session:subscribe(SPid, [{<<"forwarded/t_rpc/one">>, #{qos => ?QOS_1}}]),
+        ct:sleep(100),
         PacketId = 1,
         emqx_session:publish(SPid, PacketId, Msg1),
         ?wait(case emqx_mock_client:get_last_message(ConnPid) of