Missing packets using the nRF52840 Dongle

[IanAber]

I am using the nRF52840 dongle to watch the configuration information being passed from an Osram coordinator to an Osram 4 button switch. I am finding that there are a lot of missed packets where one of more attributes are being set in the switch but the nRF52840 dongle does not see the packet at all. Occasionally I see repeat transmissions of packets where, presumably, the switch did not acknowledge and the coordinator resent.
Is this to be expected using the dongle due to lack of radio reception sensitivity or is there a possibility that there is some USB failure getting the information from the dongle into Wireshark? I have tried two dongles and they both behave in a similar manner. Would the nRF52840DK board give me any better results?
I am using Wireshark 3.0.3 on a MacBook Pro running Mohave and the dongle is about 1.3 metres from the coordinator.
Any suggestions would be most welcome.

[e-rk]

I'm not sure if I can give a valuable suggestion here.
Since you are using Wireshark 3.x you can select in the sniffer preferences window the IEEE 802.15.4 TAP out-of-band metadata. This will show you the signal strength measured by the chip and perhaps help you troubleshoot the issue. The nRF52840 has sensitivity at around -90dBm, so if your received packets approach that value it would indicate that either the transmitted signals are weak or the antenna characteristics or the environment cause the signal to significantly degrade. You can try to rearrange your test setup and see if that helps.