A
So this has been going on for me since yesterday and only with longer text messages. Here's what I did that seemed to have solved the problem. Go into settings-messenger- text messages- input mode- GSM alphabet. Hope this helps.Checked settings in smartphone and all in English. This started yesterday morning.
I found the cause of my issue!! The texts that I received in Chinese text included emojis - both being sent from 2 different iPhones. Once the emoji was removed and the text was resent, I could read it.
Problem appears to be acknowledged as an AT&T issue. https://forums.att.com/t5/Windows-Phone/messages-arriving-on-Chinese-characters/m-p/4953709#M29262