Hi @ck25415 ,
Could you share a screen shot of your flow?
Have you selected Replace for field “If another file is already there”?
Do you have more than 100 files to be moved?
I have made a flow likes below, however, the conflict error doesn’t occur on my side.

Could you check the version history of the file to see if the file that got the conflict error has multiple version histories?
Sometimes, the save conflict error indicates the item was changed since the item was initially loaded and the update attempt was made, so you may need to resubmit the flow run to make it succeed.
Best regards,
Mabel