Samsung s7 erases messages even when they are locked

[AC Question]

I have erased messages on my phone, but I save a few of them. I put the lock feature on it and it is supposed to keep those messages and the contact. It erases all the messages and the contact disappears from the message page. Any suggestions to stop this from happening?

 

[Ca_lvn]

Ajust the setting for amount of messages to store, mine is set to all