The build-up of yeast and bacteria in kombucha is unavoidable unless it is filtered. So unless you are filtering your batches or buying filtered bottled kombucha, the sediment will always be there in some capacity.
So, while odd-looking at first, the residue at the bottom of your kombucha is entirely normal. If you don’t like the idea of drinking the sediment, you can filter it out or pour it slowly from your bottle, leaving the sediment behind. There will still be beneficial bacteria and yeast in the rest of your drink.