glvideomixer: Starting and stopping the pipeline cause memory leak (macOS)

OS: macOS 10.15.2

Platform: iMac (21.5-inch, Late 2012)

GStreamer version: 1.16.2

When I stop and run the pipeline multiple times, each time the memory keeps increasing. The code is shown as below.

#include <stdio.h>
#include <unistd.h>
#include <gst/gst.h>

GstElement *pPipeline;

gboolean replay(gpointer user_data)
{
   gst_element_set_state(pPipeline, GST_STATE_NULL);
   gst_object_unref(pPipeline);

   pPipeline = gst_parse_launch("videotestsrc is-live=true  ! video/x-raw,width=720,height=480,framerate=30/1 ! glvideomixer ! fakesink", NULL);
   gst_element_set_state(pPipeline, GST_STATE_PLAYING);
   return TRUE;
}

int main()
{
    gst_init(NULL, NULL);
    GMainLoop *gloop = g_main_loop_new(0, FALSE);

    pPipeline = gst_parse_launch("videotestsrc is-live=true  ! video/x-raw,width=720,height=480,framerate=30/1 ! glvideomixer ! fakesink", NULL);
    gst_element_set_state(pPipeline, GST_STATE_PLAYING);

    g_timeout_add(3000, replay, NULL);
    g_main_loop_run(gloop);

    return 0;
}

If I replace glvideomixer by compositor, The memory usage is fine.

Linux platform does not have this problem.