if you’ve never dusted it, or if it’s in a “high dust” area, it really could get clogged that bad that fast. if you smoke, that increases the dust, and if you are within a few feet of a vent (or up to 10 feet in it’s direct path…), that increases how much dust will get in there. I have to dust my router about 3 times a month because there’s 3 smokers in my house and there is a vent literally 2 feet away.
Not trying to force that diagnosis on you, but look into it. sometimes the most difficult symptoms are caused by simple problems and have simple solutions.