Unfortunately we can’t do much around SSL pinning yet. Not sure how deep you want to go, but there are several Frida scripts that patch common pinning implementations.

I also think mitmproxy (open source) has an option to spin up a virtual Android device that can bypass pinning via AVD. I have not tested how reliable it is though.

FWIW, it could also be a cert trust issue. I would try a quick Safari search to confirm the cert is fully trusted. ChatGPT is pinned, but the gym app makes me think it might be a trust or config issue on your device.

Happy to take a look as well. Email me at alex at zatanna dot ai.