Weird '+' appears under Khmer, how to fix this?

As you can see in the screenshot, '+' appears under the text and it isn't supposed to be there. In Photoshop I was able to fix this through by switching the text option from Eastern Asia to Middle East. In Indesign I cannot find that option. I tried using 'International Adobe Composer' but that does't solve it either.
The other threads I found in this forum didn't help me further.
Does anyone have a solution???
