A previous fix was done for DCN1 that needed to be ported to DCN2:
commit 
60c677534e73 ("drm/amd/display: Disconnect mpcc when changing tg")
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
                        }
                }
 
-               if (!pipe_ctx->plane_state &&
-                       old_pipe_ctx->plane_state &&
-                       old_pipe_ctx->stream_res.tg == tg) {
+               if ((!pipe_ctx->plane_state ||
+                    pipe_ctx->stream_res.tg != old_pipe_ctx->stream_res.tg) &&
+                    old_pipe_ctx->plane_state &&
+                    old_pipe_ctx->stream_res.tg == tg) {
 
                        dc->hwss.plane_atomic_disconnect(dc, old_pipe_ctx);
                        removed_pipe[i] = true;