You will have to download it manually. Where? Windows Update Center (or Windows Update) on PC. The update is also available in the Microsoft Update Catalog. Why isn’t KB5012643 automatically installed? Because the update is not considered critical.
All the updates included in the update will be in the future, the automatic monthly (this time in May) major update traditionally released on Tuesdays. However, if the user has encountered one of the problems described here, you should download and install KB5012643 right now.
Most importantly, it fixed a bug that could cause Windows 11 to take as long as 40 minutes to load. Experts also freed PC and laptop owners from the bug that caused the collapse buttons to disappear in open screen programs. The video no longer has crooked captions.