On Septmebr 30th. LE certs did a weird. Hence mentioned LE Certs
Are you using something like cloudflare? As Cloudflare will block the requests due to thinking they are spam/malisious/robotic attacks.
My eventsubs are working fine so we are looking at environtmental issues to your setup.
So you’ll need to check your apache/nginx logs to see if it’s actually hitting your server or not as well as any firewall logs