testing MaxScale 10.5.6 and the campaigns table still failed to load. I looked at the columnstore logs and it looked like it imported 0 rows, but it failed somewhere. Couldn't tell where.
I changed the ETL to change text columns to varchar(100) like we do on ColumnStore 1.2.4 and tried again. This worked, the campaigns table data imported without issue. So it seems there is an issue with the implementation of the text data type.