Webhook URL - Offline

Hi 

I have a CV alert that sends notifications to MS Teams via a webhook and it works fine (has been for months).

I have now duplicated the alert but pointing the notification to a different teams channel with a different webhook. The problem is that the CV webconsole says the second webhook URL is offline.

Hover over the webhook and I get > “Offline (28/07/2022 15:25:31)”

I know the webhook URL works as its used by grafana successfully and also calling from the terminal works:

curl -H 'Content-Type: application/json' -d '{"text": "Hello World"}'  [WEBHHOOK_URL]

Any ideas why CV would report it offline?

Thanks,

Mike