Why is Phone Audio check box not functioning

[AC Question]

I cannot get audio on my Huawei watch. In Bluetooth Settings on my Moto Turbo2 on the paired watch, the Phone Audio button cannot be checked. I've unpaired the watch and tried again but still does not allow me to check the box. Audio goes through the phone and doesn't allow me to switch to BT.

This used to work fine until I had to do factory reset on my phone.