I don’t know if this is a known issue. What we have is: an integration with several hooks enabled, its ownership was moved (used to be a user, now an organization), it has a single installation (still in testing) which is only enabled for one repository.
What I noticed, is that at least one other repository to sending webhooks to the integration.
“You can edit repositories that … is installed on”, only one repository is selected.
Any ideas why this could be? I could filter those out applicatively, but kind of expected it to be done automatically.