I've tried to update TrueNAS Core both via GUI and CLI and the update wont stick, it reports as still available and will attempt to download and install it again after a reboot.
Upgradebase-os-12.0-U5-e218454a694f74eee6bb23494346eaaa -> base-os-12.0-U5.1-2c2e088546e3db7e05cbdf3f818fe373Upgradefreebsd-pkgdb-12.0-U5-e218454a694f74eee6bb23494346eaaa -> freebsd-pkgdb-12.0-U5.1-2c2e088546e3db7e05cbdf3f818fe373Upgradefreenas-pkg-tools-12.0-U5-e218454a694f74eee6bb23494346eaaa -> freenas-pkg-tools-12.0-U5.1-2c2e088546e3db7e05cbdf3f818fe373
Upgradebase-os-12.0-U5-e218454a694f74eee6bb23494346eaaa -> base-os-12.0-U5.1-2c2e088546e3db7e05cbdf3f818fe373Upgradefreebsd-pkgdb-12.0-U5-e218454a694f74eee6bb23494346eaaa -> freebsd-pkgdb-12.0-U5.1-2c2e088546e3db7e05cbdf3f818fe373Upgradefreenas-pkg-tools-12.0-U5-e218454a694f74eee6bb23494346eaaa -> freenas-pkg-tools-12.0-U5.1-2c2e088546e3db7e05cbdf3f818fe373