Bitbucket.org webhook not working at all - not sending requests

For a repository we're using I've created a simple push webook to an endpoint we control. However Bitbucket doesn't even send the requests.

I've went to he "Pipelines request logs" webhook and I can see a list of requests for repo:push, but they're all old, from 18+ hours ago. There have been commits and pushes, even new branches today, even 5 minute ago, yet they don't appear as events.

The custom webhook I created for repo pushes doesn't list any events. I clicked "Load new events", nothing. I've added other events, for example repo:update, still nothing.

The webhook is active.

PS: It's not obvious to me if this ticket is private, if someone from Atlassian confirms it is I will post the repo name & co in a comment (or just edit the ticket).