Why does coffee smell good when it's brewing but smells like an ashtray once you pour it in a cup?

Your best bet is to stop smelling ashtrays. Properly brewed coffee has a wonderful aroma while brewing and in the cup.  For taste-good, smell-good coffee, spend the $300.00 and buy a Breville coffee machine. Complete control and probably the best coffee you have smelled or tasted.

If the water us too hot it burns the flavor compounds. So you can smell them being released (good) but when you drink it, it's burnt/bad. The water should be no higher than 94 degrees Celsius.  Over steeping it will make it bitter.

{Drip machines have the tendency to burn them. Get a French Press and a kettle with a thermometer in it.]

You are messed up - tastes/smells NOTHING of the sort to me. Maybe you have covid-19

Mysterious, but I have a sneaking suspicion that the dishwasher did it.