So I had a thought last night and wanted to share it - I do not know that this is what's going on, but judge for yourselves.
Magnesium is needed for many processes in the body:
Magnesium is a cofactor in more than 300 enzyme systems that regulate diverse biochemical reactions in the body, including protein synthesis, muscle and nerve function, blood glucose control, and blood pressure regulation. Magnesium is required for energy production, oxidative phosphorylation, and glycolysis. It contributes to the structural development of bone and is required for the synthesis of DNA, RNA, and the antioxidant glutathione. Magnesium also plays a role in the active transport of calcium and potassium ions across cell membranes, a process that is important to nerve impulse conduction, muscle contraction, and normal heart rhythm.
/ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ So, if I was deficient in magnesium, those above processes could be affected, depending on how far my deficiency had gone. If I started a form of magnesium that my body could easily absorb, I would then start feeling some of those processes start back up or improve. This could be mistaken as a reaction to the magnesium instead of seeing it as it helping.
Again, this was just a thought, I'm not saying that it's what's going on for anyone here specifically.