Processes in Microsoft 365 Insider for installing preview builds, activating subscriptions, and keeping apps up to date with the latest Insider features.
It appears that you may have started updating right in-between an older build being replaced by a newer one, which just happened in the 12 hours or so. Give it a little time and try again. The new build is still in roll-out, and isn't 100% available yet which may have caused the trouble.
-Jesse