The cartridge is fine, and everything is good. However, if you only use one tablet, which is always the case, the other one still gets damp because the packaging isn't water-resistant enough. If someone then inserts the second tablet, there's a high risk that it will no longer be usable.
This happened to us twice on board. It was expensive...
It would be great if the article, both on the Internet and in the paper catalog a direct link / reference to the appropriate life jacket (s) would be specified. I found it only about the amount of CO2. Otherwise, it's on board and hopefully will not be needed.