Problems adding images in Safari

[D-Coda]

Safari 12.0.1 (14606.2.104.1.1)

1. Click in the editor where I want the image.
2. Press "Add Image" button on toolbar
3. Upload Image to Magento library (or pick an existing one - it doesn't matter which)
4. Select image
5. Press insert button
6. Nothing goes into the dialogue box for the URL or preview image.

However...

If I press "Insert" on the empty dialogue box different things can happen:

The HTML for the image goes into the Excerpt field instead of the main one

or

Some strange HTML which is not for the image goes into the editor.

or

Nothing happens at all

Also...

After saving the blog and coming back to it the HTML for the images sometines gets changed or removed.

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UPDATE

Could this be an ID clash on the blog editor page? There are two HTML editors there and the images seem to get put in the wrong one.

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