@rick-novy Yes ... a bit elaborate. After several decades working with wood, cane, and bamboo flutes and the occasionally severe reactions they have to breath moisture, I have a heightened sensitivity to moisture issues.
My Sylphyo has had some "quirky issues" on the first startup of the day. A typical symptom is not responding to some finger pads for the first 30 seconds. Another is erratic response to breath pressure for a short while. The symptoms go away after 30 seconds, so I was "not a big deal", but still concerning.
I am self-diagnosing here, but it did seem to me that the problems happened the day after playing a long time (like 3 hours). They did not seem to happen the day after playing for 1 hour. The finger pads on the front side did seem to have issues (only for the first 30 seconds) if I stored the Syphyo overnight in an upside down position (i.e. front finger pads down). If I stored it front-side-up, even after playing a long time, the finger pads were not affected.
Maybe it is because of my heightened sensitivity, but I started to think that humidity was a contributing culprit. Does a bit of moisture creep out of the bore? Might it "settle" settle on the lower portions of inside of the instrument?
I hesitate to place anything that blocks moisture evaporation into the bore overnight. I have been drying with a silk cloth (oboe cleaner) and leaving it open so it continues to dry.
I have only used the fan for 3 days now, but I have had none of the "quirky issues" since. Time will tell ...