Before smartphone makers switched to edge-to-edge, nearly bezel-less designs, we had a small transition. Some smartphones rounded-off the corners of their rectangular screens to emulate the high-end look. In many cases, these phones actually just had square displays, and the effect was done in software, or via masking in the front glass. That includes the Pixel 3a. And unfortunately for folks that own one, that software masking broke at the end of last year.

Reports indicate that the problem first appeared with the December 2020 update, which disabled the additional software masking of the display's corners. That extra masking supplemented the blacked-out shape in the phone's glass with sub-pixel precision for a smoother look, giving the faux-curved corners a smoother appearance. And while the change doesn't outright break any functionality, it is a little less attractive.

It's hard to photograph, but you can see the corner radius changes depending on the angle you look at it. Previously, it was masked in software so it would look the same from all angles. 

It's admittedly a minor problem, but it's annoying — customer reports call the new look "cheap," among other things, and we can confirm with our Pixel 3a that the issue is real (and really small). We aren't sure if the problem extends to the Pixel 3a XL, though; I don't have one, and I don't know if it similarly masks the display to accommodate a square-edged screen.

We reached out to Google regarding a schedule for a fix, as affected customers have been marginally annoyed by the tiny issue for three months now, but details weren't forthcoming. Hopefully, now that it's on the company's radar, Pixel 3a owners can look forward to a fix for those tiny curved corners soon.

Source: Pixel Phone Help Forums; Reddit (1), (2), (3)