have you tried a different sd card ?

sounds like it oculd be either the card itself or the card reader playing up.

Also as what you have is a replicator clone using x3g files - have you tried Flashprint as a slicer ?
select creator pro from the machine menu and try that.
https://www.flashforge.com/download-center

I find for the rep clones it's easiest the best slicer, particularly if you ever do dual prints.