I'm not familiar with NYGM but the basics should be the same. Correct me if I'm wrong however.
Are you using automatic targeting?
If so, no you shouldn't be able to adjust target speed and range, unless you turn the tdc off but once you turn it back on it will go back to the current values of the targeting. With auto targeting, you point, lock the scope on the target, and the little triangle will change color depending on how good the solution is. When it's green, the solution is pretty good-shoot!
If you are using manual targeting, you need to turn the tdc "off" to input target data-speed, range, and AOB. Then turn it back on. Don't ever, ever, ever forget to turn it back on before shooting.

Never ever have I done that. Nope, not once. Ever.....well maybe once... or twice.
Without more information, I can't be much help beyond that.
PS-Welcome aboard!