Very cute little module! It is not clear from documentation, if the module already has an internal 1uF capacitor at the DEC4 pin. (Datasheet V2.0 says: "the module is highly integrated that contains ALL the necessary components", but a reference schematic in the same document illustrates the capacitor externally. Perhaps the manufacturer could clarify this.) So, I installed the capacitor externally (to be on the safe side - according to Nordic even 2.2uF is acceptable), and the module worked perfectly from the first try.
Great seller with great product. Fast shipping. Well packaged. I recommend this seller.