I've been doing some testing with the nRF52840 (I purchased the Raytac MDBT50Q-1M), and I'm seeing a pretty hard startup surge. I've attached the results from my scope. The power supply is 3.3V from my bench. I thought maybe I had a faulty chip, but I am seeing the same behavior on the nRF52840 Feather from Adafruit (uses the same Raytac variant).
Having said that, I did see there's a new chip revision out, but I was just wondering if this is normal? It's a pretty big drop. I added a small capacitor between the supply and ground, and it definitely smoothed things out; however, the surge is still there.