Unable to enroll in beta program on 2017 5K iMac

Hi everyone, not sure what changed, but the option to enroll for the public or developer beta on macOS Sequoia suddenly disappeared on my Mid 2017 5K iMac. It is still present on my Late 2013 13" MacBook Pro though. So it doesn't seem to be an issue related to my account. I just did a clean install of macOS (stable version) and OCLP on my iMac, but the option is still not visible. Any ideas?