I tried your advice, the problem was not solved. I power the transmitter with a 3V lithium battery with a 10 microfarad electrolytic capacitor connected in parallel to the battery. I use a manual switch to start. The receiver is powered by 3V of Arduino nano again in parallel with 3V and ground. There is no power problem because the transmitter transmits every time, but the receiver receives once and stops. If I restart the receiver, it picks up again and stops again. If I transmit data 2 times in a row (as already mentioned), the receiver receives the second data from each time. If you can try my code.