I'm having the static/snow screen display issue after awakening from sleep on my 2018 Mac mini. By static/snow, I mean the monitor display looks like the pattern an old TV using an antenna would display if it lost its signal. I returned my first 2018 mac mini because of this issue and the replacement 2018 Mac mini has the same issue. What I've learned about this issue is documented below. Apple tech support is not experienced with this issue, so, in the near term, it's up to the community of users to figure this out. Please add any knowledge or experience you have with this issue to this discussion. My 2018 Mac mini set up: OS version as of this post: Mojave 10.14.2. The mini is connected to two Samsung C24F390FHN monitors. One monitor is connected via an HDMI cable to the HDMI port on the mini and the HDMI port on the monitor. The other monitor is connected to a USB-C port on the mini and the HDMI port on the monitor. Issue Observations: The static/snow display issue ONLY occurs when the mini awakes from being in sleep mode for a longer period of time. Clicking the Apple icon in the upper left corner and choosing "Sleep" and then waiting 4 minutes is long enough to cause the issue to appear. The issue ONLY occurs on the monitor connected to the HDMI port on the mini. The monitor connected via the USB-C port on the mini does NOT exhibit the snow/static display issue upon awakening from sleep mode. I isolated the issue to the HDMI port by switching how the two monitors were connected to the mini; either via HDMI or USB-C. Since the issue followed the HDMI port and not a specific monitor, this means either monitor is NOT the source of the issue. This issue is directly tied to the HDMI port on the mini. The issue fixes itself after less than a minute. The screen switches multiple times between displaying snow/static and a black screen and then eventually fixes itself. Disconnecting the HDMI cable from the mini or monitor and then reconnecting the HDMI cable also fixes the snow/static issue. Apple's tech support recommends three standard resets (PRAM, SMC and another acronym I don't recall), which do nothing for this issue. Don't waste your time performing these resets. Apple's tech support escalation process is ineffective for this issue. The third contact on my support case for this issue resulted in a Genius appointment that was a waste of time. The Genius stated that unless they can replicate the issue, the issue is likely specific to my computing environment. Rather than leave the mini at the genius bar for a few days, I chose to return the mini (it was only a few days old) thinking the issue was likely an anomaly only associated to the particular unit I had. That's not the case since my replacement mini has the exact same issue. My Apple tech support experience gave me the impression that since the 2018 Mac Mini is so new, Apple just doesn't have enough experience with this issue yet. Don't waste your time with a Genius appointment. You may even want to consider holding off on buying a 2018 Mac mini until this issue is figured out. My next steps to get around this issue include: Try connecting both monitors via a USB-C port. As in, don't even use the HDMI port on the mini. This requires buying a new cable. If step 1 above doesn't work, then try using the HDMI port or a USB-C port on the mini to connect to the monitor via the VGA port or whatever other connection is available on the monitor besides the HDMI port. This requires buying a new HDMI to VGA cable or similar cable. Updates as of 01-16-2019. Both of my monitors are now connected via USB-C cables. Doing this replaced the snow issue after wake up from sleep with pure black screens being displayed for 20 seconds after awakening from sleep. Yes, there's an annoying 20 second wait EVERY time I awaken the mini from sleep. I also tried using an HDMI to VGA connection for one monitor. This didn't work at all. Don't waste your money trying this. The monitor connected via the HDMI to VGA cable would just constantly blink. Having been through the Apple tech support process, Apple thinks the issue is a Samsung monitor issue (of course it can't be an Apple product issue...). Apple suggested everything from rearranging cables (possible interference) to trying new cables, which I tried. I then contacted Samsung tech support and described the issue, and yes, you guessed it; Samsung says it's an Apple product issue. Getting nowhere slowly. Anyway, I borrowed an LG monitor and.....yes, the same issues exist with the LG brand of monitor. I think the Monitor, Cables and Cable Arrangement can be eliminated as possible causes of the issues. The comments from others left below reporting the same issue using different monitor brands (Acer, LG, HP) adds more data points suggesting that the monitor is NOT the issue. I've reported this information back to Apple tech support and they seem to have gone silent. Hmmm? What's left to check? Perhaps the mini itself? To be continued...dah-dah-daaaaah! Update 1-23-2019: Installed OS 10.14.3 with no change. Issue still exists and so does my Groundhog Day-like experience with Apple support. No communication back to me yet again. I guess I have to contact them and start all over again...interesting technique. Less than impressive experience.