Check all your electrical connections, your shaking them loose whenever you land from the jump and then your transmitter and receiver have to find each other again, that's where your delay comes from.

Start at your receiver pack, check the wiring, check the connector, all the way to the switch, then from the switch to the receiver.

While your at it also make sure you check your servos wires and connectors also.

If your problem persists chances are you have shaken something loose in your receiver, if you have another receiver try using it. This is probably not your problem but I have seen it before, I am betting the problem is either in your battery wire or connector.