So I've had an issue with this monitor for a while now, where when I connect more than one input, my U2518D tends to blank out or become unresponsive entirely. My main computer is connected via DP (GTX 1080 output), and I later connected a 2nd computer via HDMI (Intel HD 610). From time to time my U2518D would blank out on the HDMI output for a few seconds, then resume working again. I changed the HDMI cables, something shorter with ferrite cores to boot. Still, the U2518D kept blanking out. I later changed the 2nd computer to mDP. Still, the U2518D would from time to time blank out. Lately however, my U2518D goes to sleep and will not wake up. The only way I can wake up the U2518D is by unplugging either the mDP or DP cable. Both DP outputs are running DP 1.2, and HDMI is on 1.4. I've already tried disabling DP 1.2, and HDMI 1.4 just for trial and error, but it's just worse, causing my U2518D to start flickering on DP.

Any help?