The first possibility that strikes me when I read your issue is potassium sodium imbalance and weak adrenals possible tyroid too. The cause is uncertain for me cause i did not read your posts but my opinion is ACV has lot of potassium and you lose sodium - that is a possible reaction besides distroying candida...please read more about the connection of weak adrenals low tyroid and digestion
Same for Geoff - make sure your adrenals are ok and test yourself several times too see if avoiding or reducing high potassium food or too much toxins from digestion or too much dyeoff helps. Also make sure you reduce an underlying inflammation in the body that will help adrenals more. A subclinical inflammation or chronic undiscovered infection could keep the things this way IF the cause is not already known.
I would stick with hcl and other enzymes until things clear.
I could be wrong but might worth thinking. Everytime I have good bowel movements less inflammation less exposure to toxins my digestion improves a lot.