Good evening!

I've recently had a new ISP (Giganet UK using CityFibre if relevant) and decided to switch out the ISP router (Eero 6E pro) with the TP-Link AX53 / AX3000. 

I used the settings the ISP gave me to get set up but didn't quite work. I could ping out but showed as disconnected and couldn't browse the net. I got it down to a DNS issue. Presumably the TP-Link didn't like my ISP's DNS. I switched it to Google's DNS (8.8.8.8 / 8.8.4.4) and immediately I had the internet, seemed fine. 

However, I keep having issues connecting with certain apps from my phone, the apps mentioned in the title just freeze up and don't go anywhere. If I switch to mobile data it's fine. I'm getting 900/900 in speed and most things are fine, websites themselves seem ok, largely seems to be 'apps' .

Anyone have any insight as to what the problem could be? I don't want to have to give up, return the router and switch back to the Eero if I don't have to. I already had TP-Link extenders around the house so don't want to lose the mesh I have. 

Thank you in advance for any help!