Anton L thank you for your reply!

I do have the webhooks entered in Chargebee, in both the test and live modes. When I run the test within Chargebee it shows successful:

In Studio > Paid Levels I have copied the 'name' field

and entered it into Chargebee > Product Catalog > Plans as the 'ID'

If the Webhook is correct, I can only conclude that I must have the misunderstood where the membership 'name' is supposed to be entered into Chargebee.