[Spotlight Devices Disappearing]

Has anyone else every experienced Lighting Devices in Spotlight randomly disappearing?

For context. 
Layer Options - Show/Snap/ Modify Others
Classes - All Visible
Layers - Specific offending layer is the only layer visible.

When viewing my drawing on my Design Layer I cannot see my devices, but when I press Ctrl+A  or drag a marquee I am able to select everything.
My viewport shows my devices and tells me what layer they are on.

I was able to edit my device through the Resource manager to make sure every component was built on a visible class.
This happened suddenly and I do not know what caused it. Needed to finish the drawing so I have already deleted the offending Device from the resource manager, rebuilt it and have moved on.
However I would like to be able to deal with this without resorting to a full rebuiild.

Can anyone provide guidance on the situation?

[ISO: Vectorworks Spotlight 2019]

Hey All,

Looking to purchase a license for Vectorworks Spotlight. Ideally looking for 2019 but open to older versions.

Cheers,
Justin Hay