Unable to back up text messages on S6 edge

Hi, I am trying to back up my Samsung S6 edge (android version 5.1.1) to Samsung account using the "Back up my data" function under "Setting". The problem was that my text messages would stop at 33% and said "Backup failed: MMS". Anyone has a solution to bypass the problem without backing up using Smart Switch on my PC?

Thank you!

Hi, did you manage to get this issue resolved? would be good to hear how you did it.