Hi M,
Cryptomator does nothing bit encrypt the files in your vault.
If your vault is placed within your local “OneDrive” directory, the OneDrive app will do the sync
If you open/update/create your documents/files directly from/in your Vault , there’s nothing more to do, because OneDrive App will do the sync.
If you copy your documents from a local folder to the vault, maybe for a backup purpose, then you’ll have to use a backup software for the sync between you local storage and your vault.
(Maybe this post will help for that case)