Long time reader, first time poster.
After having difficulties with my starter after a move, I was ready to toss my starter in the trash and start over. All my bread was coming out dense, crumbly, and unpleasant after a day or two of being bagged in the cupboard. Come day 3, I could hardly squeeze the loaf and could usually tear a boule in half akin to a phone book. I tried changing everything in the process to remedy the density, from kneading by hand to machine, using different rising times, retarding the dough, etc. al. I was at my wit's end.