IOS 13.2 has so much memory management that you close applications almost as soon as you leave them. Users find it difficult to maintain WhatsApps upper dialog window and switch to safari browser to get some information because the former will reload when it switches back and safari browser will close the tag when it leaves. This problem is common on iPhones, even the high-end iPhone 11 Pro / Max is not immune.
Modern software is usually developed with the equipment shipped, and then repaired. Apples rapid update means that while users can get patches as soon as they are ready, they are also more likely to encounter more errors due to the initial rush time.