@paweld Hi, I was just reading the "Limitations" section on the official page: https://www.arduino.cc/en/Reference/softwareSerial
You are using a "Mega" board so it seems that with the SoftwareSerial library you can only use a subset of the available pins (actually the limitation is for the RX pin).

Just to confirm, could you try to use different pins as described in the "Limitations"?

Max

@parachutesj
Hi,
nrf24 radios share the same frequencies of wifi spot.
Did you check the presence of any WiFi spot, repeater or any other source of signal that could interfer with nrf24 modules?
You could check the Wifi spectrum with your smartphone. There are a lot of apps that analyze the frequencies.
Just an example: https://play.google.com/store/apps/details?id=cz.webprovider.wifianalyzer