ethanol the "1" at the end indicates you have the security preview release (which is recommended), the one with "0" is the pure open source release without this bunch of security preview patches. You can also see that if you carefully read the release notes:
https://grapheneos.org/releases#2026040800
All of the Android 16 security patches from the current May 2026, June 2026, July 2026, August 2026, September 2026 and October 2026 Android Security Bulletins are included in the 2026040801 security preview release.
By the way the current version is 2026042100 / 2026042101. If not automatically happened in the meantime, you should run an update. When did you install GOS? Cause webinstaller should always install the current stable version. Maybe the update was installed but you missed the reboot notification. Reboot after the update is necessary to completely finalize it.