It is the water, and the reason a jug filter did nothing is the most useful part of the answer.
Coffee is about ninety-eight percent water, and the minerals in it are part of the extraction rather than a background. Two matter:
Magnesium and calcium actively bind to flavour compounds and pull them out of the grounds. Too little and the brew is thin and flat - nothing is being extracted efficiently. This is the empty-tasting failure.
Bicarbonate buffers acidity. Too much and it neutralises the fruit and brightness, and everything tastes dull and slightly chalky. Hard water is typically high here, and this is almost certainly your problem: it is not that your water is dirty, it is that it is chemically flattening the cup.
Why the jug filter did not help: most of them are ion-exchange or carbon. They remove chlorine, some metals and some taste, and they reduce hardness modestly at best. They are designed to protect your kettle and improve tea, not to hit a brewing target. Filtering hard water usually gives you slightly softer hard water.
Why the bottled water worked: you happened to buy something in a much better range. Which is also why bottled water is inconsistent advice: the brands vary enormously and some are worse than tap.