Safari and other browsers not working on wifi

Hi All,

Safari and other browsers on various iOS devices ( my iPhone, my iPad and my wife's work iPhone) stopped working through my home wifi for most sites after the last iOS update (last weekend 28-May). All other native iOS apps work fine and so does any banking apps and facebook and LinkedIn and Instagram.

The same sites that don't open through wifi on iOS devices, open perfectly fine on Safari when on 4G and everything works on my MacBook as well when connected to the same wifi . E.g. time.com won't open on iOS Safari while connected to home wifi but opens on iOS Safari when connected to 4G ( and of course opens fine on MacBook safari). Please see the steps I have taken so far.

1. I have reset network settings on my iPhone and also forgot the wifi network and reconnected and also deleted all Safari history and cache as well.
2. I informed Apple support that this happened after the recent iOS update. They couldn't pin point the problem and suggested I do a full reset and restore which is way too time consuming.

This cannot be an ISP or modem issue because everything works fine on MacBook and my wife's work Dell laptop which both use the same wifi as the iOS devices.

1. I also noticed that on my Apple TV, the Netflix and Amazon Prime apps also give a network error.
2. I also notice that any apps that are wrappers around a browser like CNBC Business also stop working when on Wifi.

I will go to a shopping mall and see if it is just my wifi or any wifi that causes this problem but I am pretty sure that this is something to do with the iOS update as it is affecting all iOS devices.

I will be thankful if someone can provide any leads as to what is happening and what can I do to resolve this issue.

Thanks

Junaid