Phishtank list download fail

[revengineer]

I am using the Phishtank block list but have been receiving 403 download errors on an hourly basis even though the list is set to update daily. The error only occurs when the cron job executes or I manually select the "Cron" force update option. If I force "Reload All" then the list will download properly.

There are two issues here:

1. Why is the download failing? I have registered and am using the link with api key, which should not be limited.

2. Why is the download occurring hourly if the update frequency is set to daily?

Help much appreciated.

Thank you in advance.