Was your ACRB shredded or powdered? and did you do any freeze/thaws on it beforehand?
It's possible that the STB has not effectively broken down the vacoule's in the plant cells (where the trypatimes are stored).
If you still have the bark in containers in a basic solution (ie you didn't filter out the solids), then I would suggest acidifying the solution with white vinegar until you have a Ph around 12, and let this sit in a heat bath for several hours. Then re-basify it with your lye and pull - see what you get.
You can effectively have your solution in acid form for a week if you really like, but from what I gather, if you have your soup in a basic solution for too long, then this is when other plant fats and materials migrate over to your NPS easier.
Also, I have found when pulling with warm NPS as opposed to HOT, I get purer DMT and less NMT from ACRB specifically
If you still get poor results, it could be your material. As a backup, try using Cyb's salt-tek (or MaxION tek) with 50g ACRB. You should pull about 1g on average
Throughout recorded time and long before, trees have stood as sentinels, wise yet silent, patiently accumulating their rings while the storms of history have raged around them --The living wisdom of trees, Fred Hageneder