If you're having issues booting the latest Beta / Alpha release, we need more details. We need to know which device model you were using and whether you had any modifications to the OS. Updates are only supported with an unmodified official release of GrapheneOS and you should have the bootloader locked for verifying OS integrity.
@spl4tt You have a previous post implying that you have a modified OS:
https://discuss.grapheneos.org/d/2275-will-gos-and-root-related-issues/17
Is this still the case? That would explain why it's not working.
@v6ak @DoctorGo If you've modified the OS, we need to know that.