In the review tab, Translate/Choose translation language, it was set to Arabic.
I just copied and pasted. My defaults on this computer are also set to Keep Source Formatting. What I mean by new document, is that I opened Word, i.e., a blank from my computer, in which Arabic is certainly not, and never has been in the settings. You might try replacing the Arabic setting I indicated above, rebooting your computer, and then trying again.