Push notifications not working on WhatsApp after IOS 14.1 update

I've been using WhatsApp since the very begining on an iPhone 2G and it always worked well, but a few days ago I realized that I am NOT receiving Push Notifications from WhatsApp or if I do, they arrive very late.

I have to open the app to get the messages.

I've tried everything possible on earth except restoring my iPhone XR to factory defaults (which I won't do).

I contacted WhatsApp and they claim it's not on their side but on Apple's APNS Service. Every other app gets Push notifications fine (Telegram for instance).

It's quite surprising that searching these forums lots of people found this exact same issue related to other IOS version upgrades (13.3 for instance) and sadly they never got a decent answer.

I am regretting not having migrated to Android before. LOTS of bugs in IOS 14. My wife's 300$ Android phone behaves a lot better and doesn't have to deal with this ammount of frustation. Thanks.