Everlast, as a quick note, the formula you calculated for four dough balls is correct (using 1.50% starter):
1.50% Starter (As percentage of formula flour)
This matches your specific numbers exactly as you specified. However, there is no bowl residue compensation accounted for, which means you may not quite be able to make four 250g dough balls.
As to your issues, there could be many things:
1. Do you dump off a portion of your starter when feeding? If so, how much.
2. How long was your starter dormant before recently using it for pizza making? Was it potentially very acidic at the time of use?
3. Was the dough "very wet" after the initial mixing?
4. How sure of you of the consistency of temperature during the initial 36hr bulk ferment (you specified 65°). As a side note, when utilizing Caputo 00 flour with small amounts of starter, it is normal to see little to no visable rise during the bulk ferment.
5. What did you ferment the dough in? If plastic, any potential there are scratches in it?
6. What was the temperature in your mixing area when mixing? Was it warm to hot? I know in many areas of the country it has been very hot recently. If so, what steps did you implement to control the temperature of the doughball during mixing? Is there a potential the dough came off of the hook above 80°F? This may have potentially jump started the fermentation too aggressively, although more visable signs of lift/fermentation may have resulted from such an issue.
There is more that could be the issue, but I would suspect either the temperature got too warm and/or your starter could have been very acidic at the time of use. Granted, it is a small amount, but it could play a roll.
I had a very similar issue about a month ago. My dough was just very wet at dividing/balling time for no readily apparent reason. I gave my starter a thorough wash and implemented better temperature controls and the problem resolved itself. The acidity levels and the warmer temperatures had apparently caused an increased deterioration in the gluten matrix (thereby weakening the dough and releasing water). It sounds good on paper anyways.