Stanley Thermos Emits Disgusting Smell

I purchased a Stanley thermos for the first time, using it for water initially. However, after using it for tea and coffee, an unpleasant odor persisted in the thermos cap. No matter how much I washed it, the issue persisted, affecting both the taste of the water and leaving a lingering smell. I sent it for service on November 9th, and there's still no resolution. They promised a response on WhatsApp, but tracking the service status is impossible. If you're considering this brand, explore other options for warranty support. Don't rely on their guaranteed service. I won't choose this brand again. There are better thermos options at more reasonable prices. Despite the tag, this was a costly lesson. Structurally, the usability of the thermos, especially the plastic part, is limited and easily damaged. It's almost as if you need to use it with a cover. Oddly, for a thermos, I would say it's mediocre and not effective. Do your research before purchasing; other brands offer superior thermos options. Don't get hung up on the hot-cold retention hype. They're all the same. It's a waste of money. There are more affordable and higher-quality thermos options on the market. Just know this.