nrf24l01 communication

I have one nRF24L01 on the Raspberry Pi, and let me define this nRF24L01 as “Master”. The Master will send a signal every 1 or 2 seconds to many “Slaves” device. Initially the Master is at talking mode, after sending the signal out, the device will change to listening mode and wait for ~0.2s to receive the signals from Slaves. The Master use one talking pipe to talk to all Slaves, and use 5 listening pipes to listen from different Slaves. Basically Master needs to collect simple data from all Slaves every 1 or 2 seconds. Master is monitoring the real time data from Slave devices. There are many Arduino Nano devices, and each Nano device has one nRF24L01. Let me define these nRF24L01 as “Slave” devices. Initially these nRF24L01 are at listening mode, after receiving the signal from Master, each Nano will collect a simple data, and each Slave will change to talking mode to send the data back to Master. After the sending out of the signal, each Slave will change to listening mode again to wait for the next signal from Master. Slave’s listening pipe is using the same address as the Master’s talking pipe, and Slave’s talking pipes are using the same addresses as the Master’s listening pipes. I assume, with this setup, Master can talk and listen to many Slaves at the same time. If all Slaves send the signals to Master at the same time, I am afraid the Master may miss the data, so I command the Slaves to send the data with different time delays, for example, first Slave, upon the receiving of signal from Master, it collect a simple data and send the data back to Master "right away", the second Slave, upon the receiving of the signal from Master, it wait 5-10 ms then send the data back, the 3rd Slave wait 10ms then send the data back, … and so on. Unfortunately, the Master always miss some data from Slaves, not miss all, just miss one here, miss one there, and sometimes get worse and miss many data, so the communication is not stable. After a few cycles, Master can collect all data, but I like to make things more stable -- prefer to get all data with one shot, and I want to solve this unstable communication issue. I need some advice. To clarify, I already have the code and you do not need to write the code for me.