Bluetooth legato module errors "G_IS_DBUS_PROXY (proxy)' failed"

MangOH Yellow bluetooth legato module errors on calling bluez_gatt_characteristic1_call_write_value_sync() in org.bluez.GattCharacteristic1.c.

The error message shows :
-Nov 17 11:35:02 swi-mdm9x28-wp user.err Legato: =ERR= | bluetoothdevice[3025] | (process:3025): GLib-GIO-CRITICAL **: g_dbus_proxy_call_sync_internal: assertion ‘G_IS_DBUS_PROXY (proxy)’ failed