Hi, toggling off the min/max range isn't intended to set the min/max range to full range. It just doesn't allow any range changes to get sent to your device. If you want to restore the range to its full settings, then you'll need to keep the range toggle enabled, and just set the min/max range number boxes to 0 and 1. You should be able to cycle through the peripheral ranges until it selects the full 0 to 1 range.
I'm not sure how you set up your key bindings, but I tested the "next peripheral range" key binding on my headset, and it works for me. Make sure that your keybinding isn't triggering any other layers, and maybe check if the "previous peripheral range" key binding isn't set to the same key binding.