ConBee III (ConBee 3) from Dresden-Elektronik based on Silicon Labs EFR32MG21 +20dBm radio SoC/MCU

Maybe but probably not, more likley it is the better reception of the newer adapter, however most important is still to add more Zigbee Router devices and avoid interference, see → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage