MFwebhookserver is configured and seems the Endevor part is working well.
At B4G, when event got received, saw the following msg at server log:
Release : 18.1
Component : BRIDGE FOR GIT 2.1.1
Check the WebHook setting from MF webhook server UI, the path to the payload URL is set as http://host:port, which is not correct.
The correct format is <host>:<port>/rest/evcs/v1/hooks/mfwebhook