I am trying to create Tasks in Sales Cloud, from within a Marketing Cloud journey, but sometimes it doesn't succeed. In one instance, the journey creates 100 tasks, but another 9 fail due to 'Soft Error'. There is no Status Detail.
Looking at the Contacts, for which the tasks are supposed to be created, I cannot find anything wrong, they look just like the other Contacts for which tasks could be created.
Where can I find more detail on why these task creations are failing?