Has anyone ever seen this, when I turn on my phone and unlock it all the tiles are blank and stay like that for a few seconds before showing the correct content.
I just upgraded my Lumia 520 to Cyan through the standard path and it has the same issue. I think this is an inherent bug with 8.1. I really hope it gets fixed in Windows 10 or earlier. It's actually quite embarrassing how bad it is sometimes.
often happens on my 520 as well, usually when I'm using a background image instead of plain color tiles. Currently using 3 columns. don't know what causes this too, already tried reset
If you have alot of tiles, flipping, etc., and sometimes background pics, this will cause that problem. Also check which apps run in the background. Forgot which app that did that to me, but both cases did the same thing. 925 & 1520