This is a cheapest consumer SSD, not suited for Ceph. (You will see countless reports here in the community with similar issues with consumer hardware and Ceph)
You purchased a support subscription (support contract).
Start reading on https://pve.proxmox.com/pve-docs/pve-admin-guide.html#sysadmin_package_repositories
Really? You never read the complete admin guide? Highly recommended and the primary source of information.
https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_frequently_asked_questions_2
Hab die Frage schon beantwortet, nein, tausch einer HDD ist nicht die Ursache.
Ich habe den Key zurücksetzen lassen, bitte einfach auch "Check" am Admin interface klicken.