Why am I not receiving some texts from only one person?

[AC Question]

I have a samsung galaxy ace 2 and I don't receive some texts from the same person, then I might text them again later and I will receive their reply to that text... It's very frustrating... One night all the texts I hadn't received came through at the same time and sometimes when they answer my text the end of a text which I never received might be mixed in to the end of the text they just sent... it's very confusing and I don't understand why it only happens with one person. I always get texts from everyone else. Please help!!

 

[LibbyXCX]

First choice would be to reboot. The choice i think will work is Factory resetting it, Thats what fixed mine when it was like that.