Yep, I’ve had that same bad luck with an English roast. Wouldn’t recommend that for the pot roast in the crockpot. I’ve had great results with 7-bone chuck roast and chuck shoulder roast (bone-in or boneless).
I like the way you’re deglazing the pan and adding that to the crockpot concoction. Good stuff!
I never heard of a 7-bone roast. What is that?
I have a butcher who leaves the bone in for me. It really does make it better.
An English roast is a perfect candidate for braising, which is what pot roasting is.
When a roast is braised, the fibers contract at first, as the collagen is dissolved into the liquid. After much time cooking, the fibers relax and reabsorb the liquid , producing a moist, flavorful meat which falls apart easily. So you may be serving the roast too soon. 8-9 hours in the crock pot on low would probably not be too long.
Another possibility is that you may be using too little liquid. Dry cooking will make tough cuts of meat tougher. I prefer a couple cups of beef broth and a cup of dark wine. (More liquid is okay). I thicken the juice afterward to a thick sauce and it tastes as good as that served in a fine restaurant.
When the English roast is done, cut it into thin strips across the grain. It will be very tender.