Not Getting Calendar Notifications on iPhone 13, v. 18.5

For almost a year now, I am not receiving ANY Calendar Notifications on my iPhone 13 (v. 18.5). It didn't happen right after any upgrade, nor did I change any settings. They're not coming through on my MacBook Air either (Sequoia 15.5). This is happening to old recurring appointments as well as new ones I make. I rely on these Notifications not only for appointments, but for critical medications both my husband and I must take on certain days at certain times. Now I have to look at the Calendar every morning to see what's in store for that day and beyond. I should not have to do this, but I can no longer rely on technology.

BTW, every appointment I set is marked as "Time Sensitive," and my Settings reflect that. And calling Apple Care has not helped.

I appreciate any assistance!