Is there any way to bulk re-subscribe users in Marketing Cloud?
I currently have lots of users who are held, undeliverable or bounced in their _listsubscribers status but whose email addresses have subsequently been changed on Sales Cloud vs. Marketing Cloud.
From this article it seems I need to update to unsubscribed then to active: https://help.salesforce.com/articleView?id=000322262&type=1&mode=1
But I obviously don't want to do this manually so have a data export and import set up with a query that identifies everyone who:
 has a _ListSubscribers status of 'held' or 'bounced'  has a different email address in Sales Cloud vs. Marketing Cloud based on our synchronised data extension (linked to the more accurate/up to date Sales Cloud database)  has not opted out of email on Sales Cloud
Everything seems to work as expected except the _ListSubsribers statuses for the relevant contacts aren't actually updated following the automated .csv import.
The automation currently goes:
SQL query - verification target data extension isn't empty - data extract - file transfer to FTP - data import from FTP to Marketing Cloud.
Does anyone know if there are limitations I'm not aware of that are stopping this from working or if there is a better way of achieving this?
I have tried updating the subscriber status to both 'unsubscribed' and 'held' using the import.