how to delete ble object in app designer

I built an UI in App designer to read data from a Arduino BLE (bluetooth low energy) device

problem is I couldn't use 'clear' or 'delete' functions to disconnect from the device, 'clear' doesn't do anything and 'delete' pops an error saying that ble object cannot access the delete function, so far the only way that works is to close the app

is there any other way to do this in codes??