Sulfur smell and taste in fermented drinks

[AlienSkyler]

i have noticed for a while that my kombucha would taste like sulfur if i used certain kinds of juice for the second ferment
i made some ginger soda with kefir whey and it tasted like sulfur
i looked it up and it doesn't seem like the sulfur smell and taste is harmful or dangerous, but it's not appetizing and i wonder if something has gone wrong with my kombucha scoby
i purchased the scoby probably a year or so ago from Happy Herbalist, it was a scoby that supposedly contains S. Boulardii
i did this because i learned more about what a healthy scoby is supposed to be like, you shouldn't be able to put your finger through it, and before that i was making kombucha with a scoby grown from store bought kombucha and apparently it doesn't work so well to do that anymore
my scoby does not seem to be as healthy now, and i don't know if i need to buy another (i don't want to) or if there is some way to maintain it
i have at least recently been trying to trim it and remove less healthy parts, a really small but healthy looking scoby appeared in a bottle of kombucha and i added that back into the main brew
i'm worried something has gone wrong though, some sources said the sulfur flavor can mean the scoby isn't healthy anymore, but the sulfur flavor might only be a thing with second ferments, i just noticed it in some root beer kombucha that is otherwise really good, and basically i just hope my kombucha is still healthy and don't know how to tell if whatever is causing the stuff to taste like sulfur is also giving me gas or if that's an unrelated dietary factor
any advice?