Why did i lose a few random messages?

[AC Question]

I was looking for pics of my Great-Grandpa, sent to my phone by my mother and they are not there. They were all sent in one message and seem to he the only messages lost, also I upgrades from Samsung Galaxy S5 to an S8, and also some po pics are missing from gallery that I know I transferred to the S8.

 

[B. Diddy]

Welcome to Android Central! How long ago were the pics sent, and were they sent via text message? If so, did you ever download/save the pics on the old phone? If you didn't, then those pics wouldn't have been transferred over from the old phone to the new phone.