Distilled water only draws out used minerals.
It cleans the kidneys as it passes thru.
We get our minerals from foods and not from water.
Most minerals in water are non useable by our body and most likely one of the causes of kidney stones.
I am not sure, but most RO filters have Lanthanides. Dr Clark said the only one that she tested free of Lanthanides was the Nimbus Water Maker mini.
Maybe it is a higher amount of ions or cations?
Have u ever tested their RO water with a TDS meter?
Perhaps, there is some differing solids than what you are used to.
RO is usually 0-5 TDS.