When I switched to mango a few months ago (I'll have to make a blog article about that some day, so you know why, but mostly it's the monocle layout, awesome for apps that don't like tiling), I also started using Noctalia, which adds "DE-like" functionalities to a window manager.
But then, I also...
On arch and other distributions, for many reasons, you might need to repair stuff that went wrong after an update, if you rebooted before fixing the stuff that broke.
Repairing the bootloader, reinstalling a mandatory part of the system, it's all doable without reinstalling.
So, sway is an awesome window manager, but to stream/screenrecord correctly without black flashes... you need to disable something called direct scanout.
To do this, you must pass an environment variable in the config file used by login managers to start sway.
It is located at /usr/share/waylan...