VMs appearing as 'offline'
Let me just chime in on this and try to shed some light...
There are two distinct reasons why a VM would be declared as 'offline'. One is if the VM has been previously backed up by Pure but is now no longer present in the vSphere inventory. One example of this is your recent case where a VM was deleted in vSphere and you had to restore it from Pure. This was the first and the original meaning of offline - VMware counterpart to our VM is currently not available. Backups are temporarily suspended but you can restore normally.
However, a VM will also be declared as 'offline' if there already exists another VM (in Pure) that corresponds to the same vSphere VM. (e.g. if you somehow got to the situation where you have two nix-projects-2018 VMs in Pure, both of them referencing the one and only nix-projects-2018 VM in vSphere). Because both VMs cannot function in parallel without getting in each others way, Pure will examine the situation and choose the best VM out of the group. That one VM will be active and will be shown in its corresponding ESXi host section in the list. All other VM duplicates will be declared as offline. In this regard, the fact that nix-projects-2018 is shown as offline in Pure does not mean that the VMware VM of the same name is offline (in fact, it is shown as online later in the list, in the dell-2 section). But because this particular VM is a duplicate, it cannot be backed up, only used for restore.
Maybe I should have insisted some more on creating a separate category for these cases but because the behaviour is very similar, they are for now all grouped as offline.
I haven't manually checked each and every VM in your screenshot, but I checked half of the 'offline' VMs and they are all correct. In each case, Pure has at least one, sometimes two more VMs with the same name (referring to the same vSphere VM). In all cases, the VMs in the offline list are the ones with older backups while the VM that is in the main list has the most recent backups. This is as it should be. FYI, comparison is performed each time a new VM is added to Pure but since you only use one backup volume, this should not influence you.
The VMs that have their scheduled backups disabled are all NEW VMs - they have no backups so far. This means these are newly created VMs. There is a configuration setting in AppConfiguration page that decides whether newly discovered VMs should have their automatic backups enabled.
You can find more info in our Knowledgebase article: