Updated to clarify questions regarding as Home Assistant posted video showing interference symptoms:
@agners since it was released have read/seen quite a few reports from many users saying they specifically have serious issues with electromagnetic interference symtoms with he Home Assistant SkyConnect dongle, even when using the original 0,5-meter long USB extension cable that ships with Home Assistant SkyConnect to a USB 2.0 port as recommended in order to get it away from the computer and pheriphials, so wonder if there should be any special concerns regarding those specific symptoms that are unique to the Home Assistant SkyConnect and the short extension cable it ships with that makes it extra sensitivity to electromagnetic interference compared to other Zigbee Coordinator adapters?
Can you confirm or refute that the USB extension cable that ships with Home Assistant SkyConnect is a properly shielded cable with adequate shielding to protect it from all electromagnetic interference if used in a USB 2.0 port (or a powered USB 2.0 hub) and place it as far away from the computer and other pheriphials/devices as the short USB extension cable that ships with it allow?
And have you tested if conductor shielding of the USB extension cable that it ships with is properly grounded to the plug connector on both sides?
Also, wondering why the EFR32MG21 SoC and other sensitive components such as the crystal oscillator chip and capacitors on the circuit board of the Home Assistant SkyConnect does not have a grounded metal shielding cage for electromagnetic shielding that would protect the EFR32MG21 SoC and all sensitive circuits, and design it so that the board only exposed the antenna?
To compare with the Silicon Labs EFR32MG21 based reference radio modules, the MGM210 series (MGM210P and MGM210L) does come with a grounded metal shielding cage for electromagnetic shielding that protect the EFR32MG21 SoC and all sensitive circuits, only exposing the antenna:
https://www.silabs.com/wireless/zigbee/efr32mg21-series-2-modules
Asking now as seen a few reported interference symptoms what at worse sounds somewhat similar to the interference problems that plagued the original ITead Zigbee 3.0 USB dongle/stick/adapter based on Silicon Labs EFR32MG21 (Model: 9888010100045) which among its infamous poor antenna design issue as well had a circuit board that did not have a grounded metal shielding cage for electromagnetic shielding that proved to make it much more sensitive to electromagnetic interference (EMI, also called radio-frequency interference or RFI) and external sources caused by electromagnetic fields.
For that original ITead Zigbee 3.0 USB dongle/stick/adapter based on Silicon Labs EFR32MG21 (Model: 9888010100045) the interference sensitivity made it so bad that it was practically useless unless the user added some DIY solution for grounded metal shielding cage for electromagnetic shielding, such as putting Kapton tape on the components for isolation and then wrapping it in conducive metal tape as sheiling.
Then there is the question about the choice of using a circuit board PCB antenna instead of a ceramic chip antenna, as official MGM210 radio modules from Silicon Labs. Why not a ceramic chip antenna?
I understand there are many different pros and cons with ceramic chip antennas and circuit board PCB antennas, but I understand one major benefit with good ceramic chip antennas is that they are easier to tune perfectly, which indirectly makes them less sensitive to electromagnetic interference if implemented optimally, while I understand that a major downside is that ceramic chip antennas generally offer lower performance, however making them easier to tune can compensate for that.
PS: My personal feedback is that it should instead shipped with an even longer USB cable regardless.