For some time I already have this issue. Sometimes the Play security update status disappears from the settings. Usually a data and cache wipe of the Play Store and a reboot fixed it. But I’ve done this a few times now already, still gone.
I have the playstore deactivated, so just for my understading: in the screenshot above you would have an extra entry7line with the security update date of the Google Play Store? Is it the same as under settings-about the phone-Android 11-Google Play Systemupdate?
Hmm strange, also in safe mode I don’t see it pop up. I guess I’ll give it some more time. Sometimes it also took a while for it to come back. Hopefully in a few months Android 12 will be released, then I’ll do a factory reset and hope this stabilizes.