Random app freezes after waking from sleep?

I'm running a vanilla install of Mojave (10.14.1) on a Gigabyte Z370N-Wifi, i3-8300k and internal graphics, with 8GB Crucial Ballistix memory.

Everything seems to be working properly, except when waking from sleep. After waking the computer from sleep (usually longer than 10 minutes), I start getting a number of apps freezing. Chrome will not open at all -- I get a grey screen. Safari freezes on certain websites and won't play any videos from any source. It freezes on the new reddit (but not the old), Youtube, Amazon, or any other video/media website. Firefox works a little better, but will still randomly freeze. Preview gets stuck on opening certain documents, but not others.

With all of these apps, I either need to close the tab (Safari), or force quit from the activity monitor/dock. Restarting the computer fixes all the problems. I can use any of these apps/websites properly, but after the computer sleeps for a longer period of time, all of the problems immediately return. I don't even know where to begin. Has anyone encountered this problem before? Any suggestions on where to start?