Originally Posted by
StephaneM60 If download speed is Ok and upload is 0, this may be because you have installed something on your phone like an ad blocker or a vpn software. I'm using Adguard and with the nperf speed test application I'm getting 0 on upload if Adguard is active.
Bingo! I had been having a related problem whereby, on mobile data, the S8+ stock browser was being choosy as to which sites to pull up and which sites to hit me with a blank page and "the site can't be reached". Was driving me nuts, and I came very close to calling my provider and telling them to get their collective ass in gear, lol.
That's when I read your post and knew immediately I'd hit upon the solution. I had been using a private DNS for system-wide ad blocking, which you can do with Android Pie — turned it off, tried accessing two particular sites I hadn't been able to, and both showed up immediately.
After that it was a matter of switching to another static DNS server and trying it out, and … so far, so good. We'll see. But at least now, I know what the cause is should the problem reoccur. Thanks man. I um, love you.