My NRF52840DK does not seem to be working correctly after programming the nrf sniffer firmware.
I am using the instructions for setting up the sniffer provided here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fug_sniffer_ble%2FUG%2Fsniffer_ble%2Fintro.html
I downloaded the sniffer firmware from the following page and have attempted 4.1.1, 4.1.0, and 4.0.0 with the same outcome: https://www.nordicsemi.com/Products/Development-tools/nrf-sniffer-for-bluetooth-le/download#infotabs
Screenshot of nrf connect programmer used for flashing the dev kit for reference:

After programming the firmware I see the jlink connection continuously cycle. I have tried this with two different dev boards and see the same result. I also occasionally see the jlink run in bootloader mode as shown below.


Within wireshark I see the nrf com port intermittently available under interfaces, but am unable to establish a connection and successfully sniff packets. Either the port will disappear or attempting to connect will fail.
Any help with troubleshooting this issue would be appreciated!