Random black border bug on screen

[Firat]

Hello I recently noticed a bug on BalenaOS (I think it’s a bug)
When starting up, I have black borders on my screen.
When these black borders are present at startup, my chromium application is also impacted by these borders.

Here is another image, at startup the borders are no longer present.

What changed between the two tests? Nothing at all.
I simply unplugged my pi4 and plugged it back in and magically the borders disappeared

Here is our fleet configuration for what is related to HDMI

This issue is present since balenaOS 3.1.1 until the latest version.
Why do we sometimes have black borders when starting the OS, which also impacts our chromium browser?
and why these borders disappear from time to time after restarting RPI4

[mpous]

Hello @Firat could you please confirm what display are you using and the ressolution?

Thanks

[Firat]

Hello,
I use a beetronics screen: Écran tactile 12 pouces haute luminosité | Lisible au soleil
with a resolution of 1920x1080.

[Firat]

Hello again,
no one has any idea about this bug?

Thanks

[alanb128]

Just to confirm, are you saying this did not occur at all on balenaOS versions older than 3.1.1? Also, have you experienced these borders when trying a different model of monitor?

[Firat]

Hey @alanb128

in fact, until today I had never noticed this bug on versions prior to 3.1.1.
We also tried with several screens and the problem persists, I would however like to point out that the issue is random, and that sometimes a simple reboot of the device can fix the problem.