Credit and Credit URL disappear in overlay view (but works in page view)

Hi.

I have a problem when editing an image in overlay mode (coming from the “grid” Media Library view, as opposed to the “list” Media Library view).

Steps to reproduce:

1. From WP Admin, go to Media > Library
2. In the toolbar, pick “grid” view
3. Click an image to edit it
4. Add a Credit and Credit URL
5. Click to the “Next” or “Previous” image
6. Click back to the original image

Expected behavior:
Credit and Credit URL entered earlier will be in their appropriate textboxes.

Actual behavior:
Credit and Credit URL entered earlier will be in their appropriate textboxes, but they are both “greyed-out”. And if I click to the “Next” or “Previous” again and come back, both fields are empty.

Alternatively, if I go to Media > Library, use “list” view, then “Edit”, then add the Credit and Credit URL, then Save and come back, what I enter into those fields stays. And, if I then go into “grid” view and edit, the Credit and Credit URL are both there, in regular font, even after clicking “Next” or “Previous” and coming back again…

Mac OSX 10.11.6
Chrome 66, and FF 59
WP 4.9.5
Media Credit 3.2.0

Also replicated on colleague’s iMac, unsure of OS, but also recent Chrome.