Phone not always receiving instant messages on time

I have a persistent issue with my Pixel 7a Android 14 phone, that messages sent through WhatsApp don't always get received on my phone until a while (30+ minutes). Sometimes they don't get received at all until I grab my phone, in which case they all get received at once, and in some cases they aren't received until I actually open the WhatsApp app and there I will see them all rattling in. I suspected Doze Mode to be the culprit, but the issue persists even after disabling battery optimizations for the app. I have also tried using other applications such as Skype, Instagram, which experience the same problem. I have also completely deactivated Do not Disturb and it does not solve the issue either. Reinstalling WhatsApp has also not solved the issue. The issue is not with the sending phone - they communicate just fine with other people on WhatsApp during these problems. What is happening? How do I make my messages received and notify me when they should?