Whistling after shed?

[WifeOfSlasher]

Okay... after many struggles we have temps and humidity nailed after we moved. Ambient is about 82, hot side is about 88-90. Humidity is about 55%. Night drop is about 75-78 ish and 85 ish on the hot side with mostly stable humidity. We were using aspen and literally just switched to Cyprus mulch to stabilize things. Which brings me to the whistling. Dr. Google says this is a sign of an RI BUT he displays no other signs. No gapping or open mouth, no other sounds, never has even hissed, no excessive yawning, no bubbling of any kind, mouth looks perfect inside. He doesn't whistle before shedding but does after a shed, which he did last night. This is the second shed in a row that this has happened. Its also only heard when he's active. At rest, no whistle. Any thoughts? Maybe he just has a tiny amount of shed stuck around his nostils? Last time it lasted maybe a week then nothing. No sound coming from him at all.