> Yep I see this on AT&t's post paid network with my Pixel 3A XL as well, one > place I really noticed it causing issues is with Facebook and Instagram > where Facebook requires constant captions to view any Facebook links I > receive and embedded Instagram content in news articles and things of that > nature often failed load. It is very annoying.
> > Tmobile US, VZ, and Sprint all have IPv6, but only AT&T has this behavior > > afaik. HTTP proxies are used by some mobile carriers to down-scale media sent thru their radio network to reduce bandwidth. They rationalise that, e.g, a HD video can be down-scaled for a tiny screen with no real loss of fidelity but a signficant reduction in bandwidth. Similar strategies apply to almost all compressible media: mp3, jpegs, etc. More often used outside the US as I recall but sounds like AT&T might be doing something similar. You could try a mobile fetch of a known media file via HTTP and HTTPS then compare them for possible insights (make sure to use a mobile browser to avoid browser-detects). Such proxies are sometimes used for carrier ad-insertion as well so one presumes they detest the widespread switch to HTTPS for at least two reasons. Mark.