External Drives repeatedly not showing up in libraries

It strikes me that external USB drives, within Libraries, repeatedly disappear. They are available in Explorer library, but within Opus they are gone.
Am aware that I already brought up this issue in an earlier thread:
Libraries-External USB Drives-not showing up-even though properties are showing them - Help & Support - Directory Opus Resource Centre
(@Leo - Hesitated as to whether or not to revive that thread, but having some new information (screenshots) I believe I should create a new thread. Feel free to migrate this one into other, if you think it is better)

Anyway, things went fine for some time, but regretfully the issue returned since -say- last week or so.

Screenshot shows USB drives are showing up within Windows Explorer, but not in Opus.

When checking out 'Properties' (Opus) the drives are displayed.
I might click "Add" but then Windows Explorer is launched showing the drives within Libraries, i.e. there is nothing to add.

Not sure how to proceed.

Any suggestions?


(Edit: I think I got confused about what the issue was, as your screenshots have most of the context cropped or blanked out.)

I'm not sure what is going on there.

Can Opus access those drives directly?

Yes, Opus detects the drives, they do no show up in library. They have been added to the library in the past. Windows Explorer does shows the drives.
The drives should show up under folder "Films".
(For your info: when r-clicking that folder > Properties, then the drives are in fact listed (i.e. under Properties, but not under Library)

If the drives aren't always turned on and plugged in then it's probably that which is causing the problem. (As per the old thread you linked.)

Reason for re-submitting this is that Opus does list the drives under the Library > Folder >Properties.

Also the fact that they do show up for a longer period of time, after multiple pc shut downs and "safe removals of the drives". Even when not using the drives for a week or so.
So my non-expert guess is that something is causing this(?)

That aside, to be honest and no offense meant, I can hardly believe that on this matter a dramatically poor product like Explorer seems to be doing better than an outperforming Opus. Again, no offense meant.

They show up now, I have no idea why. Went into the folder's properties, then changed the "Optimise this library for:" from 'General' to 'Videos' + apply. Most of the files are in fact video files.
Now they show up in Library. Beats me . . .

I expect that if the drives aren't plugged in and turned on when Opus starts, or when it first lists the libraries, then they won't appear in the libraries until either a full restart of Opus (File > Exit Directory Opus), or something which causes the library to be reevaluated (editing the library's properties).

They weren't designed for drives that aren't there all the time. It doesn't really make sense to put them in libraries, IMO.