https://www.tp-link.com/jp/home-networking/wifi-router/archer-ax23v/
 

I had no problem setting up the network (PPPoE) and all my devices can connect to the internet with no issues.
Nevertheless on my android devices (both with latest Android OS) some applications are so slow that are basically unusable.

Other apllications does not seem to be affected.
For example WhatsApp works as expected.

Following are some of the apps that do not work properly.
Naver LINE (Whatsapp-like Japanese app)

Misui-sumitomo VPASS (Japanese banking app)

There are actually more app that are not working properly.

Please not that:

- This is is not present when using my old router (google wifi)

- When I am outside my home network (e.g. at work or connected to cellular network) everything works fine.

So far I have tried turning of the ISP firewall, but it did not help.

I admit this issue is not easy to troubleshoot.
Any help would be greatly appreciated.

Thanks a lot in advance