My 2017 Latitude recently starting doing the same thing. But only for my wife's texts, all others came through. Convenient one might think...lol. She was getting REALLY annoyed that I never responded, I had to have her sit in my Jeep and text me to prove I wasn't being a dog.
I removed my phone from bluetooth pairing on the uConnect, deleted the Andriod Auto app on my phone, re-paired my phone, re-installed the app, now all is well.
Why did it originally refuse texts from her ? No idea. I just know that starting over fixed it all.