White dust coming from the AC in a Camplite 21RBS trailer

[smoky]

When we started the AC for our 2nd week long outing in our new 2017 Camplite 21RBS a cloud of white dust blew out of the AC ducts and covered everything inside the trailer. This dust continued to accumulate over the next day (I'm writing this 24 hrs after turning on the AC). We hadn't noticed this dust during a previous week long time in the trailer. There were about 5 weeks between these two trips, during which the trailer was closed and locked. The white dust has a little shine to it when on a finger tip and held up to the light. The trailer was located near St. Louis, MO, during hot humid summer weather, so it isn't accumulated wind blown dust or similar dry stuff.

A search of the internet pulled up a couple posts with similar descriptions. One said it was probably debris from the trailer construction and once cleaned the problem would not reappear. Has anyone had a similar issue with their Camplite trailer? If so, what was the cure? My wife has asthma and the dust in the confined trailer scares her.