Make sure it is a “powered” USB 2.0 hub, meaing that the hub should have its own external power-supply AC-adapter, (all USB devices including a Zigbee radio adapter can also show other weird symptoms if they do not have enough/correct power all the time). Like for example this one → https://www.amazon.com/AmazonBasics-Port-USB-Power-Adapter/dp/B00DQFGJR4
I am afraid that using some kind of USB extension cable to the Zigbee Coordiantor is really a must, even if it is not as very long, the longer you get it away from your computer and any other devices/cables the better, so just moving it a little way might be the night and day difference between working and not.
A tip is that there are inexpensive USB over RJ45 extension adapters you can byy (sold as a pair with male and female USB ports) and they can convert any Ethernet cable into a very long passive USB cable on the cheap (though a high-quality “shielded” Ethernet cable is recommended for radio adapters). See for example this one → https://www.amazon.com/Male-RJ45-Female-Extension-Adapter/dp/B083W3D65G/
Anyway, check out this video which clearly shows how bad things might work when the Zigbee Coordinator is too close to a USB 3.x device/cable:
That is good, however still suggest you consider buying one or more of the IKEA Trådfri Signal Repeater or Sonoff dongles, as having more of those spread out around your home should give great coverage. The more “known good” always-on Zigbee Router devices that are available the more robust network you get and it will then be able to better handle if one of the Zigbee Routers goes offline temporarily or permanently, so one of the keys to a stable Zigbee network can be said to simply to add loads of Zigbee Router devices.
Suggest that you consider upgrading the firmware on it to a later version than what shipped with it if you have not already. I believe that the latest have some issues reported for it though so perhaps try the latest “develop” version if you dare. See → ITead's "Sonoff Zigbee 3.0 USB Dongle Plus" (model "ZBDongle-P") based on Texas Instruments CC2652P +20dBm radio SoC/MCU and Z-Stack_3.x.0 coordinator 20230901/20230902 feedback · Koenkk/Z-Stack-firmware · Discussion #474 · GitHub