When a synchronization begins, by default, all the current status are stored and the status is changed to Processing. This way, the system avoids a new update when an item is changed.

Once the synchronization is over, the process restores the indexers to its status original and begins a full reindexing.


You need to take into account that the indexers could be reactivated in the middle of the synchronization, generating incorrect data in the index tables, in case you have an external plugin ( for example,  Elasticsearch) controlling Magento indexers or in case there is any modification through console.

If you want to manage the indexers through any of the above channels, the option of Managing the indexers in Sales Layer plugin should be deactivated.