After the latest macOS Mojave update yesterday (10.14.6) when I activate Alfred bar through the cmd-Space shortcut and I have a VLC player window open, the bar itself is not clearly visible (but is functional) and visual artefacts (in purple colour) litter the screen.
Please see https://imgur.com/qbpHd2g
I don't know if it's the update, VLC or Alfred fault.
But before the update, VLC and Alfred was working together without problems.