The KB5021866 update, which will upgrade the OS Build to 22621.1028 and 22623.1028, was just made available by Microsoft for users of the Windows 11 Insider Beta Channel.

If you're still curious, the Insider Beta Channel has two different build variants: Build 22621 and 22623. Build 22621 has new features that users must activate first via Vivetool because they are not active by default, whereas Build 22623 has all features shown in Insider Beta already present by default.

Some additional information: This month, specifically for Insider Beta and Dev Channel, the Feedback Hub page will now display a Quest tab. If you complete the Quest, users will receive a badge shortly after the Bug Bash is over; the Bug Bash will take place from today, December 7, to next week, December 12; the Bug Bash will start on December 7.

This is evident from the subsequent Microsoft announcement:

"December 2022 Bug Bash: On December 7, Insiders in the Dev and Beta Channels will start to notice quests appear in the Input Hub that addresses various scenarios we're interested in hearing feedback on.

Use this chance to test out some new features and let us know how it goes. The Bug Bash will take place from December 7 at 12 a.m. PST through December 12 at 11:59 p.m. PST. After the Bug Bash is over, participants (who submitted feedback or finished quests on the most recent builds for their channel) will receive a badge in the Feedback Hub."

Is this KB5021866 update bringing anything fresh to the table? sadly, this version does not include any new features; however, if you are searching for fixes, this update has a number of them, including:

Fixes present in Build 22623

• Made another fix to address explorer.exe crashing repeatedly in safe mode.
• Fixed an issue where, with the system tray design updates, auto-hiding the taskbar would stop working after you had interacted with the hidden icons flyout.
• Made a small refinement for tablet-optimized taskbar users to make it a bit easier to expand the taskbar without invoking the Start menu.
• Fixed an issue that could lead to the taskbar jump lists and preview thumbnails not appearing in the correct position for Insiders with 2-in-1 PCs.
• Improved the transition animation when switching between collapsed and expanded views of the tablet-optimized taskbar.
• The tablet-optimized taskbar should collapse more reliably now after launching an app from the Start menu.
• Fixed an explorer.exe crash when using Alt + F4 with the show hidden icons flyout in the system tray open.
• Updated the battery icon's tooltip to let you know if your device is charging slowly.
• Fixed an issue causing the top half of the media controls in Quick Settings to be missing sometimes.
• Fixed a GDI handle leak in recent builds related to receiving certain types of notifications. 
• This could cause UI issues or explorer.exe crashes for Insiders who receive a lot of notifications.
• Fixed an issue that was causing the NVIDIA icon in the system tray to show empty notifications.
• Fixed an issue where, with the system tray design updates, auto-hiding the taskbar would stop working after you had interacted with the hidden icons flyout.
• Made a small refinement for tablet-optimized taskbar users to make it a bit easier to expand the taskbar without invoking the Start menu.
• Fixed an issue that could lead to the taskbar jump lists and preview thumbnails not appearing in the correct position for Insiders with 2-in-1 PCs.
• Improved the transition animation when switching between collapsed and expanded views of the tablet-optimized taskbar.
• The tablet-optimized taskbar should collapse more reliably now after launching an app from the Start menu.
• Fixed an explorer.exe crash when using Alt + F4 with the show hidden icons flyout in the system tray open.
• Updated the battery icon's tooltip to let you know if your device is charging slowly.
• Fixed an issue causing the top half of the media controls in Quick Settings to be missing sometimes.
• Fixed a GDI handle leak in recent builds related to receiving certain types of notifications. This could cause UI issues or explorer.exe crashes for Insiders who receive a lot of notifications.
• Fixed an issue that was causing the NVIDIA icon in the system tray to show empty notifications.
• Fixed an issue where the sleep recommendation on the Energy Recommendations page and Battery & Power page was sometimes inconsistent.
• Task Manager colors in light and dark should display correctly now for people with their mode set to Custom.

[NEW] When using the search box at the top of Task Manager, Task Manager may become unresponsive.

Right away, please update your Windows 11 Insider Beta via the Settings > Windows Update > Check for Updates page.