There was a problem spawning a call to the WP-Cron system on your site.

I’ve been seeing this error on WP-Control for a few weeks. It seems now that none of my scheduled events are running, like UpdraftBackups.

There was a problem spawning a call to the WP-Cron system on your site. This means WP-Cron events on your site may not work. The problem was:

Unexpected HTTP response code: 403

I know nothing about WP-Cron and I certainly didn’t change any configs related to it. I asked my host and here’s their response:
Please contact the WP-Cron provider since it is where the error occured. Disabling plugins and themes wont affect the WP-Cron system. The reason why the WP-Cron events is not working it is because of the said plugin it self.?
Why would I have a WP-Cron provider? I’ve not had one for years and years. Do I now need one? And if so, how would I get one?
Thank you,
Mike

The page I need help with: [log in to see the link]