Yes, it is only single channel gateway and is not LoRaWAN compliant. The full functional gateway can receive 8 channels and SF7-12 simultaneously.
About facing the poor antenna quality, please recheck it. Make sure it fit. We choose antenna from well known manufacturer. We got 5-6 km LOS in field test. I checked quality of our stock by Antenna Analyser and add the test result on product page. VSWR is very good and the freq is matched.