Vivik,
Initially the most critical item to check when making you own board is the XTAL frequency. The frequency needs to be correct, that is with +/-20 parts per million or +/-500 hz at 26MHz. Depending on what test hardware you have available there are various methods of checking this.
A RF spectrum analyzer is the easiest. The RF PLL will multiply the XTAL frequency up to say 915MHz and you can use a spectrum analyzer to check how much the carrier frequency is off. If you do not have a spectrum analyzer you can use some TI development kits and SmartRF studio and sweeps the band for RSSI and manually make a plot of where the center frequency is.
I believe this is the root cause of what you are experiencing. If they are off enough the transmitter will be outside the receive bandwidth filter of the reciever and nothing will work.
Regards,
/TA
