@jackpot Can you eliminate that it is a hardware/wiring problem? Maybe swap the RX and TX code on the two Photons and see if your original RX says it is TX’ing? Or physically swap the radios around to check that there is not a bad connection (those little boards are not easy for prototyping connections).
How are you powering it? USB should be fine, but have the units fairly close (within a foot or two) and dial back the transmission power say to 5 or less. Since you’re using the HW version it will consume more power and I’ve had issues before on the non-HW version that things start failing above certain power levels.
You can also test setting the HW setting to FALSE that will not employ the additional power amplification registers in the module. Once you get it transmitting successfully you can start increasing power settings or testing power setup/caps, etc.
EDIT: Note the HW requires up to 120mA during transmission, thus the need to dial down the transmit power