Duplicate status does not seem to be relevant, both because the issues described are different (flickering vs. completely black screen) and because the other bug is not marked as "Won't-fix" because it was reported on Artful.
I can confirm I have some form of this problem on an LTS release (16.04.5), computer is desktop and I only have the single monitor (Dell P2415, connected with high speed HDMI cable). Flickering happens intermittently (seems to happen more when I hover on icons in the launcher).
Duplicate status does not seem to be relevant, both because the issues described are different (flickering vs. completely black screen) and because the other bug is not marked as "Won't-fix" because it was reported on Artful.
I can confirm I have some form of this problem on an LTS release (16.04.5), computer is desktop and I only have the single monitor (Dell P2415, connected with high speed HDMI cable). Flickering happens intermittently (seems to happen more when I hover on icons in the launcher).