Q: Can't Receive Pictures in Messages when on Wifi

Different ones, Netgear, TPLink and my home router which is a Virgin Superhub

Did you try to set the phone back to factory settings, without any backup used afterwards, set up personal settings manually, and test iMessage after that?

Use iTunes to restore your iOS device to factory settings - Apple Support

Hey

after days of resetting my phone and going through the same issue ive found the answer!!!

follow this instruction

If resetting your phone's network settings doesn't work or you have to do it constantly, you can try changing your Wifi DNS to use Google's DNS.

To do this for your wifi connection via your phone:
1. Go to Settings->Wi-Fi
2. Tap the "i" info icon next to your Wi-Fi network
3. Edit the DNS field, changing the value to 8.8.8.8
4. Exit Settings
5. Your Wi-Fi will reconnect and you should be able to send pictures via iMessage

This change will need to be re-applied if you ever choose "Forget This Network" or reset your phone's network settings. A more permanent fix is to set your router's primary DNS to 8.8.8.8.

Hope this helps