Most failures on this IEM are due to the full metal built of the external shell causing drivers to drown over time, which is why blowing air has worked in your case.
Water tend to condensate below the mesh while listening because the shell conduct cold from the outside to the nozzle inside the ear.
Most IEMs don't suffer from this because they have a plastic nozzle acting as a thermal insulant, or a shell made of several parts that don't conduct heat/cold.
The only other IEM that has this defect is Fidue Sirius, with the same all-metal shell.
When you're done listening, please soak up condensated water below the mesh by applying a paper tissue, that should help preventing drowning of the microdriver.