Ongoing problems with water filter

I bought a Berkey last year and have always had 'stinky' water in the bottom resevoir within 24 to 48 hours after filtering. It's hard to describe the smell..unpleasant metallic like,maybe??
I connected with the company I bought it from and he suggested the dye test which I did and it had no problem. He had no other thoughts.
I am filtering from a city water supply.
Would a different bottom resevoir ( instead of stainless steel)change this?
Anyone else had this issue?
Any and all suggestions/thoughts greatly appreciated.
Thanks
Kate