I recently purchased some nRF52840 Dongles for evaluation.
I installed the nRF Connect SDK v1.4.1 and attempted to build a few of the sample projects using the SES(Nordic Edition) v.5.10b and v5.30a, targeting the nRF52840. I was able to successfully compile and build some of the sample projects, for example the Zigbee light_switch project, other's won't build at all.
I then tried to use the nRF Programmer to flash the dongle but there appears to be something wrong with the hex file(I suspect the address ranges aren't correct) and i cannot write the image. The only option available is to reset the device.
I have seen others having similar issues and have tried some of the options given but no luck. For instance when using the SES Nordic edition i do not have any linker or pre-compiler options available in the Project Options.
Seems like i didn't have the correct boardname when configuring the SDK project.
Was selecting the 'Thingy', not the Dongle.
Have you checked whether the examples you are having an issue with is supported on the nRF52840 Dongle? You can see supported boards under the "requirements" part in the documentation of the example…