Microsoft has released Windows 10 Insider Preview Build 18917 (20H1) to Windows Insiders in the Fast ring

What’s new in 18917
New download throttling options for Delivery Optimization
Narrator improvements
Windows Subsystem for Linux 2
Windows Ink Workspace Updates

General changes, improvements, and fixes for PC
We fixed an issue where some users experienced a 0x8007000E error code while downloading the build due to high RAM consumption.
We fixed an issue where users couldn’t use the desktop Features on Demand “add a feature” option.
We fixed an issue where dragging the emoji and dictation panels was unexpectedly laggy.
We’re in the process of rolling out a change in this build to address an issue where if the taskbar was set to autohide, launching the Start menu would first hide the taskbar before bringing up the Start menu.
We fixed an issue resulting in the Start menu and taskbar going 100% transparent on secondary monitors or after projection.
We’ve updated the new File Explorer search experience to now be dark when used in dark theme. Note – this experience is still in the process of rolling out. Thanks everyone who’s tried it so far and shared feedback, we’ll let you know when the rollout expands.
We fixed an issue where Windows Security would crash if launched from Settings when using an Arabic display language.
We fixed an issue where the audio service might hang on shutdown if spatial audio was turned on.

  Windows 10 Insider Preview Build 18917 released