The Bedrock Dedicated Server for Windows Preview is not updated on https://www.minecraft.net/en-us/download/server/bedrock
and the download button still refers to the previous Preview version (https://minecraft.azureedge.net/bin-win-preview/bedrock-server-1.21.0.21.zip). In addition, https://minecraft.azureedge.net/bin-win-preview/bedrock-server-1.21.0.22.zip returns a BlobNotFound error code.
Hi!
Can you confirm that the correct Preview server is downloading for you?