Certain apps not working on WiFi _ Xperia XZ1

[MK201]

Hi, 

On my home Sky WiFi network only certain apps work. For example Facebook and Instagram work perfectly fine but Twitter, Amazon and Ebay won't load at all. Any suggestions on what could be causing this problem? Thanks 

[JohnB440]

Im having the same issues.

I can send text via Snapchat but not pictures, I can receive pictures though.

I cant log into eBay or search on eBay. This only happens on my phone.

I've tried everything. Reset router, restarted phone, cleared cashes. Nothing worked.

Any help there Sony?