I have done this many times, different cars different receivers.
Right now it works fine on my novac 27mhz & airtronics tx. But I am trying to re config with a Spektrum DX6i and AR6100. I get the Green flashing so I pull full forward throttle, then get the red flashing light and beeping so then you go full reverse, but the ESC never excepts it.

The process is the same as using a Mamba max.
I have changed throttle trim, ESC dead band setting from large to default 1000ms
How do I get this DAMM thing to Sync !

?
Wasted an hour of my time tonight.
I am getting really Sick & tired of dealing with these syncing issues, even had to send it back once before.
Thanks guys