I believe there's a setting that affects whether the update checker looks for "optional" driver updates, or only "recommended" (WHQL) driver updates. If you don't have it set to look for optional driver updates it won't find 19.12.3.Radeon Adrenaline 2020 v.19.12.2 doesn't know that 19.12.3 exists. Check it out on the Settings page. Click on "Check for Updates".
AMD Releases Adrenalin 19.12.3 drivers addressing several issues from the 19.12.2 up.
AMD Releases Adrenalin 19.12.3 Drivers: Stability Ups and Fixes Inside : Read more