Ye. And it also feels bit spongy.
But if so many healthy people are experiencing it, then it may be just normal.
I experienced the same thing and started researching on internet, no definite answer at that time so I started to eat foods, super foods that strengthen lungs, cleansing lungs with pineapple fast, bcx ultra rife machine, oregano oil, gemstones, essentials oils, aerobic exercises etc etc, you name it. the sound is still the same after years of noticing it. So, I guess, it might be just how lung used to be. We just never noticed it. If there is no other symptoms like pain etc, then it could be normal.
But as a precautionary note, people who consume dairy and eggs are prone to lung diseases because these 2 accumulates mucus.
And too much salt retains water in lungs too.
And living in dusty area or close to polluted area like main roads are also not good for lungs.