Why does dictation not work when connected to Bluetooth?

I like to have my iPhone X connected to Bluetooth in my car so I can play music, but when I want to use dictation to send a text with my voice while driving, connected to Bluetooth, it does not work properly or register what I said, or that I said anything at all. It simply makes the sound and does not register the words. Please provide an update to fix this as soon as possible.