comments:
I'm assuming you have a newer iPhone with USB-C. Unlike Lightening cables, you can't just buy any cheap cable and have it work flawlessly. You have to invest in a quality cable. I have had the best luck with the Anker Silicon USB-C to USB-A cables. Silicon is really nice in cars too because they don't kink or tangle up like this braded cables or hard rubber ones. I got 2 for $14 on amazon. This one specifically: https://www.amazon.com/dp/B0CRZ4LR9K?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_7
Have you tried restarting the phone (Siri, restart my phone) and restarting the headunit? To restart the headunit, press and hold both knobs until the screen goes black (just over 10secs). Also, are you running the latest firmware on the headunit? You can connect it to your home WiFi and then find the software update menu option to update it. I know you said you tried other cables but unlike Lightening, most USB-C cables suck. I tried a few and had bad experiences until I got a silicon Anker.