I’m going to push back on the file format a little… In general it is best to save Photoshop duotones as PSD files (if you are going to be printing or exporting PDFs from InDesign)

But you do need to get clear about whether your printer is printing with a spot color or just CMYK (process) colors.

LOL!

Colleen is right!
Some more info here:
https://creativepro.com/indesign-secrets-video-hide-content-grabber.php

However, some people really like it… see: https://creativepro.com/taking-another-look-at-the-content-grabber.php

Yes, that could absolutely be the problem. I discuss color management issues exactly like this in my course on InDesign color management at Lynda.com.

You can use Edit > Convert to Profile in Photoshop to see what RGB profile was assigned to the image. (Then click Cancel, because you probably don’t want to use that feature other than just getting that information.)

That is very strange. It should not work like that. Are you holding down the Option/Alt key when dragging that corner point? If so, then you are making a duplicate of the object when you drag.

If I understand correctly, this feature should help:
https://creativepro.com/rid-empty-lines-data-merge.php