The lockscreen randomly displays squares instead of characters. This began to happen after OTA Lollipop 5.0.1 upgrade on a Samsung Galaxy S4, but I've also witnessed it happening on S6.
Perhaps, but the image was pushed OTA by Rogers. Not something I can fix, rather an issue with the OS. Off hand I do not know the OS version of my S6, but have experienced the same result on the Lollipop release from Rogers.
The device was of course reset after upgrading the OS. Powering down the device addresses the issue temporarrly for a few weeks.
You can change the lockscreen image via the Settings Or on your Gallery. You can pick a image & then set it as your background lockscreen image. So it could just be the image supplied via Samsung ( Not Rogers as ROGERS does NOT have anything to do with it. Making that clear as well). Try that & see.
The S6 / S6 edge is on 5.0.2 meanwhile some other devices are on 5.0.1 or some on 5.0.2 but different builds. So they are not all the same.
It could just be the image that Samsung supplied & it could be that the image does that time to time. This is best to ask Samsung Canada about.
Lockscreen image changed, issue remains.
I understand where the build comes from, but are you positive Rogers does not modify the image in any way prior to pushing out OTA?