@cosmas
What is the content of the 'config' file before you start the Docker container and after?
As per https://github.com/abraunegg/onedrive/blob/master/docs/usage.md#performing-a---resync - a resync is required when the following options are changed:
drive_id
sync_dir
skip_file
skip_dir
skip_dotfiles
skip_symlinks
sync_business_shared_items
Additionally, if you modify your 'sync_list' file, this also triggers this requirement.
A hash file is used to determine if the file has been changed, changing a single character in a comment will trigger a check of the 'config' or 'sync_list' to determine if something has changed, so the current backup of the files are read in, so that they can be compared with the current actual files.
If there is then a difference in the options being used, then this flags that a resync is required.
So .. either these options are being changed by Unraid (and given the config file is being updated - and I know that the 'onedrive' client does not do this) - this is why I am advising this is not a 'onedrive' bug or issue .. it is to do with how this has been integrated with this platform.