HappyModel Sail sky-X Not starting.

[FoamyDM]

I recently bought the toothpick quad the HappyModel Sailfly X, I can NOT get this this quad to arm/spin the motors.
I have followed the instructions best I could (which was enough for the Mobula 7HD)

• Tested the motors in the motor tab - Check. they all work, the right way.
• Linked the Transmitter - Check
• Checked the FC is receiving all the signals - Check. (the bars wiggle appropriately
• the Modes are set and responding - Check
• Battery is charged.

EVERYTHING points to all is good. I disconnect the USB, plug in the battery wait for the tones, and the lights are solid showing transmitter connection.
Nothing.
toggle the arm switch in case I have it wrong (I don't - checked)
Still Nothing.

The seller suggests I check the throttle range is from 1000-2000.
What could it be? Is there any other things I should check?

Right now, I'm stumped and sad.

I am an admitted quad noob. Only last year was something functioning that uses acro (BetaFPV 65s lite). but I have been following, educating myself and this has not been from lack of trying.