Hi Esmat,
Sorry to hear you've been having these connection issues since the latest updates.
Have you tried resetting the network settings already? You can do this under Settings >> General management >> Resetting >> Reset network settings. It might be worded slightly differently, as you're on the Dutch community, I've had to translate it myself
😉I had a similar issue before the update, and this fixed it for me. However, you do have to log in to your networks again, so make sure you know you WiFi's password before resetting.