Hi Ernesto and @lukas,
I actually have the exact problem as Lukas. I registered the RFM95W + arudino pro mini succesfully via OTAA but it doesn't send any messages (stuck at EV_JOINING). Furthermore the same setup does work if I use ABP. In addition I also have a working setup with OTAA and the RN2483. I am unsure what the problem is.
A side note @ernestopace
Could you change
APPSKEY[16]
to
APPKEY[16]
in your post with the code. As you state the correct key right after that I assume it is a typo, but it might cause some confusion.