My well water is not chlorinated but it is a bit alkaline. It works well for dark beers, but for light colored beers I switched to RO from Walmart. That helped, but I still struggled with a slight bit of astringency on the finish for the past year. I was crushing too fine, mashing too long and at too low of temps. I went through every step in my process with a few goals. My mash efficiency was near 90% and now is closer to 80%. More on what I did in another thread after I taste the last beer.
Start with good water and carefully control the mash and fermentation temps. I’m not saying you don’t have an infection to chase down, but your results sound familiar to my experience of late. Brewing is easy. Consistently brewing better beer than commercial craft brewers, now that’s a challenge. Cheers Steve!