Hi,
I don't have all your replies but in order to get more consistency you should be more precise when you make your dough, and as Tom Lehmann would say, your recipe has to become a formula: you have to weigh everything (in grams), if possible check all the temperatures (finished dough, room, fridge...), and be consistent in all the timings (example: today you let the dough half an hour more than usual, you think it's no big deal, but today is 5° hotter than usual and you didn't pay attention but you added more yeast in the dough... So today the dough inflated much more than usual... You know what I mean?). So when your result is different from one time to another, if you are consistent in your procedure, you should be able to spot which stage is failing (at least, which one is not).
I hope this advice can help you!