Some images dont display after publishing

I have a text with 10 images, used the (+) button to insert the files into the text. (upload from my computer)
All images generated the same way.
They all show perfect in the text editor.
But when I publish only 5 are visible, the others show the broken link logo.
If I right-click on that, and select [Open in new tab] the images open perfectly visible.

My workaround:
I can make those 5 broken ones visible by cropping the (vertical) sides into a less wide image.

But am sure there is a better way in Ghost itself. Is this in the Theme? Will not be able to do myself, but maybe somebody could give a hint which I can forward to somebody else who can fix it.
Many thanks.