Border artifact when playing videos

[WeaponX1]

sway version 1.0

Hello,
This is a minor bug and is only noticeable when border pixel values are changed (ex. from 5 to none) when playing a Youtube video (full window) in a container.

To reproduce the bug:

1. Assign: bindsym $mod+t border toggle
2. Open qutebrowser or chromium and play a video on Youtube
3. Create a split so you have the video running in a container (full window in a container) and the other app next to it (ex. urxvt).
4. Focus on the video container and execute the toggle: $mod+t and while going through the different modes (you should notice at the bottom right corners a thick white line artifact displaying at a blink of an eye and then disappearing)

This is annoying because I have a shell script that changes border values from 5 to none (simulating a border highlight that fades after a delay) when I move around/focus through containers. This works smoothly in every situation except when a container is playing a full window video where white bar artifacts are displayed but fortunately they fade away.

It's just annoyance at this point and was wondering if there's anything that can be done about it. I use an integrated Intel Haswell graphics card (don't have a PCI video card)

Any tips or suggestions are welcomed.