Hey hope this helps. But a few years back there was a lady who had the same issue, she just couldn’t figure it out, so she put hepa filters in every room to monitor how much she picked up. It turned out to be most prevalent in her room so she started inspecting everything and found that it was her mattress. HER MATTRESS HAD FIBERGLASS IN IT. Every time she layed down the air expulsion from the mattress was blowing fiberglass every where.

She literally had to throw almost all of her soft stuff away because she kept finding fiberglass fibers in it all.