Apple released macOS Mojave 10.14.6 Supplemental Update on Thursday. This patch was specifically released to fix an issue that prevented some Macs from not waking up sleep. To that end, here are the brief patch notes for the release:
The macOS Mojave 10.14.6 Supplemental Update fixes an issue that may prevent certain Macs from waking from sleep properly.
You can download the update through Software Update if you’ve already installed macOS Mojave 10.14.6. You can also download the standalone installer from Apple’s website, where it’s a 954.8MB download.