Did you actually ask your region's composting service whether you can really throw them in there, or are you just assuming it's fine because it says so on the package?
The thing nobody tells you straight up is that "compostable" and "biodegradable" are totally different. A compostable package will theoretically break down into compost in industrial facilities under ultra-controlled conditions - stable temperature at minimum 58°C, precise moisture levels, regular aeration, the whole deal. Your home compost? It never does that. You're at 20-30°C tops, humidity changes with the weather, and if you're not constantly aerating it becomes anaerobic. So yeah, your bags stay intact. It's not that you're doing it wrong, it's just that these packages literally aren't designed for your situation.
What's actually weird though is the marketing. They slap "compostable" in big letters on the package knowing full well that 99% of people are gonna throw it in their home compost or at best in the trash. The infrastructure doesn't really exist to collect and process this stuff at scale. So you end up with waste that *feels* "eco-friendly" on paper but pollutes just like any other standard plastic. Honestly, before you buy this kind of product, check if there's a specialized recycling center near you, otherwise it's just greenwashing.