This was an issue with the DNS servers set on the node. The default OVH DNS server was not picking up their record (even though it was set many many hours ago) so the lookup was failing and causing pufferd to be unable to authenticate with PufferPanel.
I'm not able to replicate this issue. Do you mean the symbols change when you use the PufferPanel file editor? If it's only when you reload the plugin I don't think this is a PufferPanel issue, since the files appear to be saving correctly, at least they do for me.