I was able to get dust into my new NP3. The IP68 rating does not mean that dust cannot enter. There’s a lot of people not understanding how the ISO/DIN test for IP68 works.
It’s based on observable particles and the test it conducted with particles of a particular size and, for example, plaster dust is smaller and made it’s way into my NP3.
I don’t sweat it as it’s standard usage, IMHO.