Retest canvas structure with groups at the start and end after release of celery 4.6
A celery chain having a group at the beginning and end and any more than one component in the chain is found not to complete. An issue was raised. The celery developer have tagged this for version 4.6.
Need to re-check the failing canvas structures in GWCelery and possibly re-implement them to what they were originally.
Celery 4.6 is expected to be released on September 30, 2019.