Antenna's: We picked up a 900 MHz 5 dbi antenna off Amazon for $6 and had been using it on our Single Channel Gateways for testing. My nodes still have a red wire antenna and I looked up the length for 902.3 MHz(79mm). For fun I opened up the 900 MHz antenna on the SCG and was surprised to see it was 56mm long(tuned for 1.2GHz). Thankfully I was able to remove a grounding sleeve, trim that back and create a 78mm(915 MHz) antenna. I suspect Aliexpress and eBay versions are the same.
Check your antenna lengths because even commercial ones don't tell the truth.