Why does 'Fix Alpha Border' effect JPGs?

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:bust_in_silhouette: Asked By brainsick
:warning: Old Version Published before Godot 3 was released.

I’m trying to import displace_2.jpg into Godot 3.0 (rc1-ish; self compiled) as was done in this sample.

In the Import properties, if I uncheck Fix Alpha Border and Reimport, the preview in the Inspector goes black.

JPGs don’t have an alpha channel, so what is happening here?

Edit: This behavior is apparently impacted by other settings. I’m:

Import As: Texture, Preset… 2D
Compress:
Mode: Lossy
Lossy Quality: 0.7
Flags:
Repeat: Enabled
Filter: On
Mipmaps: On
Process:
Fix Alpha Border: Off (unchecked)

Edit 2: Great; it’s inconsistent. Without making any changes, just Reimporting repeatedly, the preview goes black and fixes itself intermittently. Assuming bug.

Edit 3: Removed tags.