One caution before you go down this road, and a note on the other end of it.
Do not brew with distilled or fully softened water on its own. Water with essentially no minerals extracts badly, tastes hollow and flat, and is corrosive to some equipment. Softeners that work by ion exchange swap hardness for sodium, which does not help extraction at all - so a house with a water softener can produce worse coffee than one without, and people are surprised by that.
The target is not soft, it is balanced.
And the honest ordering of what matters in a cup, since water is fashionable at the moment:
- The beans, and how fresh they are
- The grind and the recipe
- The water
- Everything else
Water is a real and often overlooked variable, and it is not going to rescue stale beans or a bad grinder. Your case is a good one specifically because you controlled everything else and moved location: that is a clean experiment and it points at the water unambiguously.
Also worth doing while you are here: descale your kettle. In a hard area it will be furred, and a scaled kettle contributes its own flavour on top of everything above.