strange texting problem

[grissea]

Having an odd problem with my phone (S4 mini). Every now and again when i send a text, it will add a few lines to the bottom of the text from a really old text - this is actually on the SAME text, not re-sending old texts but adding old words to the bottom of new texts when they are received. From what I can tell, these are only from within conversations with the same person. Any ideas?