First of all, read and follow this best practice guide regardless of which Zigbee gateway solution you are using → https://community.home-assistant.io/t/guide-for-zigbee-interference-avoidance-and-network-range-coverage-optimization/515752
Also note that you can not have more than one Zigbee gateway solution connected to the same Zigbee Coordinator adapter. If you want to use more than one Zigbee gateway solution then you need to buy more Zigbee Coordinator adapters as each needs it won separate dedicated adapter, (though tip is that it is not actually recommended to use more than one Zigbee gateway solution at any one time anyway).
That is a common symptom of electromagnetic interference, check out ZHA docs → https://www.home-assistant.io/integrations/zha#zigbee-interference-avoidance-and-network-rangecoverage-optimization
Again, strongly recommend that you read and follow all the best practice tips (regardless of which Zigbee gateway solution you are using) and watch the linked video there which clearly shows what can happen with interference → https://community.home-assistant.io/t/guide-for-zigbee-interference-avoidance-and-network-range-coverage-optimization/515752
The adapter will probably work fine with that configuration if you get it away from interference. Connect it via a USB extension cable to a USB 2.0 port (or powered USB 2.0 hub) and not to a USB 3.0 port/hub.
Looks like have not configued radio adapter type as “ezsp” in which case Z2M defaults to “zstack/znp”.
Log show zigbee-herdsman failing to connect to the serial adapter (because is tries “zstack/znp” adapter) so likley wrong adapter settings → https://www.zigbee2mqtt.io/guide/configuration/adapter-settings.html
If you are using Zigbee2MQTT Docker Container then also probably need to configure device using Docker Compose or manually forward serial device from the host machine to the Docker instance.
See example for Zigbee2MQTT configuration.yaml specifically for Home Assistant SkyConnect, but note that the ZB-GW04 dongle (a.k.a. easyiot stick) might use a different speed for baudrate (though it probably uses 115200 too) plus it probably do not use Software Flow Control instead of Hardware Flow Control and if so need to set rtscts as false (or remove it as default for rtscts is false).
serial:
adapter: ezsp
port: /dev/serial/by-id/usb-Nabu_Casa_SkyConnect_v1.0_-if00-port0
baudrate: 115200
rtscts: true
deCONZ/Phoscon does not support non-deconz adapters, it is only compatible with ConBee and RaspBee adapters, and you will never ever be able to use any other adapters with deCONZ/Phoscon. See → https://phoscon.de/en/conbee/software and https://phoscon.de/en/app/doc