Issue resync without any change


I installed latest nextcloud version 2 days ago and everything is working fine to download file on my windows computer with windows client.
I have 200Go and sync was OK
I have only one account and I use it on my 2 computers to sync the same folder
My issue is nextcloud sync some files each day whereas they aren’t modify. I don’t understand why it does it ? I don’t do nothing with these file, but they need to be synced again. He remove my content folder to create new one exactly identical for me…

Additionnal information : I use external storage cifs

Could you help me to solve this issue please ?
I had owncloud 8 before and it was perfect with the same configuration.