Your process is an old trick to make meat dishes like ribs.

Usually you want to slow cook so that the meat reaches an internal temperature of 70°C. The tough, chewy collagen tissue is broken into smaller gelatin molecules that melt, baste the meat and taste delicious. It's that shiny gooey liquid in the bottom of the dish. This is the internal temperature to achieve falling apart tenderness of slow cooking.

At lower temperature of 60°C the tough, chewy collagen tissue starts to denature without melting. It is almost like cooking egg white - the protein is changing but it's not breaking. As a consequence, the meat can shrink by 20% in size and it becomes very chewy. Leave it at 60°C too long and it squeezes out all of the moisture from the meat and gets really hard.

You cannot recover from partially cooked meat. Not unless you do other tricks such as marinating with vinegar, or pounding it with a hammer. or essentially steaming it to get moisture back inside.

The trick for the ribs is cook them until falling apart tender, then put them in the fridge overnight. The gelatin will set really hard. Next day, you heat up the ribs just enough to denature the gelatin, and you have falling-apart-delicious-tender meat, but the gelatin has denatured and set hard, so the meat stays together for serving without being disintegrating at first bite.