Has the second alert been removed from Apple Calendar?
I had the second alert in calendar right up until I updated to the latest iphone os on my iphone 13. I have not changed any settings everything is exactly as it has always been. The second alert disappeared after the update. I checked my other iphone 13 which still has the older version and the second alert was still there. I then updated my second iphone and sure enough the second alert disappeared from that phone as well. Remember different regions may have different changes. It is unhelpful to say your second alert is still there if you are in a different region. My region in New Zealand. I also mentioned this to my friend who has an iphone 16 and his second alert has gone as well
iPhone 13, iOS 18