Is there a lot of RTL script in the text and/or the reference list?
And just to make sure: you mean actual RTL, not just right-aligned?

Have you tried switching to a different citation style and back?

Are you saying that your text looks exactly like this?

1.
?siht ekil yltcaxe skool txet ruoy taht gniyas uoy erA

Or:

2.


Does it look like this, with
lines aligned / justified to the right side?
Or, are words spelled backwards
like example 1?


When you switched to the new style, did the RTL problem go away or did it exist with the new style?

What style has the problem?
What languages are you using in your document? What languages are used in your references? Is any of the text of your document presented in non-Roman characters?

(Non-Roman character sets include Arabic, Chinese, Cyrillic, Greek, Hebrew, Japanese, Korean, Tamil and Thai, etc. Non-Roman RTL languages include Arabic, Farsi, Hebrew, etc.)

edit: What language is set as default for your computer and your software?

Please answer all of the questions (some of which may have been added as you were replying.)

It is very likely (from your answer #2) that this is an issue with your MS Word style setting if the same problem happens when you switch to a new style.

Yes, this is likely something in your Word settings. You can try backing up and deleting Normal.dotm with Word closed to reset your Word settings, and then trying in a new document.