FYI, EZSP adapter support is still experimental in Zigbee2MQTT’s zigbee-herdsman → [WIP]: EFR32 EZSP adapter implementation and test · Issue #319 · Koenkk/zigbee-herdsman · GitHub (so if want more stable then it is recommended to instead buy a CC2652 based adapter like ITead’s TI CC2652P based “Sonoff Zigbee 3.0 USB Dongle Plus” which was renamed to “ZBDongle-P .
Regardless of the adapter used, be sure you first read and try follow all tips/advice here before troubleshooting any deepder → Zigbee networks: how to guide for avoiding interference and optimize for getting better range + coverage