No I dont think so, I have flashed a new built firmware, with no settings saved, to W8980. First I was using HH5A and same thing was occurring with my phone.
Well in any case, I tried stopping firewall and flushing iptables entries but it's still the same on my phone. Although traceping showed rather better results but the official twitter app is still crappy for me. 3rd paty twitter apps and other devices on my network still working fine. Now I am forced to believe that something actually may be wrong with my phone. Because I have 2 more android devices and they work fine.
Yes I can access twitter from vpn just fine with the official app. I have been doing that for a couple of months. I want vpn to be the last resort thing because I know it works. But why does the normal internet not work?
But then twitter works on my other devices without VPN and on my phone it works when getting internet directly from ISP router. So I really dont think it's an ISP issue. Maybe something between my phone and OpenWrt doesnt work as expected. So I think it could be an issue with phone's wifi maybe.
As you may know I was having issues with some websites and as it turns out they may be getting throttled in my country to some extent and it could be one of the reasons they were not working but anyway I was able to make my ADSL connection faster for me with the help of rectifying DNS issues. I was searching online for any help regarding slow internet and some forums suggested to use PingPlotter and DNSBench. I think they are Windows based programs but may be available for Linux systems but I am not sure.
The thing is you may only need to do it once though. So yeah just use DNSBench first and get faster DNS addresses that may be available for you in your area. You can also add any DNSs that you specifically want to test and are not available in the list. My ISP was using some DNSs which were not helpful so with the help of the above software I was able to add 3 servers to my DNS list, basically in WAN interface, which improved my internet connectivity.
For me these worked but you may find something else:
39.39.39.39
208.67.220.222
8.8.8.8
Yes I think this also depends on where you live, your ISP, etc. I mean it's not just DNS related, there are more things to consider but still thanks though.
Edit: This can be related to something broken within OpenWrt System becasue right now @28-Feb-2019 I am using Snapshot and the websites work just fine with simple config changes to start internet with pppoe.