Problems with Right to left formatting

I’m trying to get some right-to-left Arabic text on the same line as some left-to-right. Here’s what it looks like:


What I want is for the (1377) to appear next to the word ‘Ibn’. But if I put the cursor next to the letter I and start typing, the new text appears further back on the line - like this:


I get the same effect typing this message. Here is the text copied and pasted from Scrivener:
Presenting Ibn Khaldūn and his Journey West and East, التعريف بابن خلدون ورحلته غربا وشرقا (1377) Ibn Khaldūn

I start typing ‘(1377)’ next the word Ibn and this happens:
Presenting Ibn Khaldūn and his Journey West and East, التعريف بابن خلدون ورحلته غربا وشرقا (1377) (1377) Ibn Khaldūn

But if I type ‘some test text’ next the word Ibn this happens:
Presenting Ibn Khaldūn and his Journey West and East, التعريف بابن خلدون ورحلته غربا وشرقا (1377) Some test text Ibn Khaldūn

Copying and pasting does not work either - the (1377) always appears to the left of the Arabic.

What’s going on?

How can you see where the Right to left formatting starts and ends?

And also, if I do Format/Paragraph/Writing Direction, there is an option to do ‘Right to Left’, but never an option to do ‘Left to Right’. Is this as it should be?