Hi @_Pietro, let's review internally with the people who ran that CTF Event "Meraki MV Capture the Flag - West" and we'll get back to you. Thanks! ... View more

They actually replied on May 16th that it was supposed to be fixed but when I tried it wasn't. I gave up and moved on. Did it eventually start working for you? ... View more

FYI, as the answer in this thread ultimately alludes to, we require a self-signed root as part of the uploaded chain in addition to any intermediates required to validate the end-device certificate. ... View more