Just spent a few hours trying to figure out why the VM was impossible to access via SSH and Linode’s recovery console.
Very difficult to say what the cause is, but for a few seconds I did see BPF errors in the console about not being able to find something.
Booting rescue image, chrooting and installing 6.5.12-hardened fixed it.
If anyone has their GitLab account - feel free to report this. I don’t and they have registration disabled.