3yr old son crying about daycare

First time poster here. I dropped off my 3 yr old son at daycare this morning and it broke my heart. He cried at home this morning when he realized he was going to daycare today (he goes 2.5 days a week). We had a good drive there telling stories and laughing, but when we turned on the street off the daycare his lip started quivering and he was holding back tears. Once we arrived, I picked him up and he put his head down on my shoulder and I just waited with him for a couple minutes. The daycare worker who greeted us at the door was very nice but wasn’t one of his favorites. He started crying again and said bye to me. As I was leaving, he suddenly realized the door was closing and waived to me one last time with tears in his eyes but he wasn’t crying hard or screaming.

For more context, we picked this daycare after referrals from good friends who send their kids there and in-person visit. We are close with two other families who send their kids there and have never heard a bad word about it from them. We hire one of the daycare employees to babysit for us on the side and my son loves her. His best friend is also at daycare but unfortunately the friend only goes one day a week. The owner of the daycare plans field trips that my wife attends to observe all the dynamics and the owner also invites our families to kids b-day parties where all the families who send their kids can socialize. The daycare uses an app where they send us pictures of my son every hour and updates on food, diapers, and other events.

Despite all of this logically seeming like a good situation, I feel heartbroken seeing this sadness in my son and how he tries to be brave holding back tears when we drop him off. I try to give him space to feel sad and comfort him physically and emotionally and my wife does the same. It just feels so wrong to see our son in pain from being left there everyday when he is so innocent and pure. I know we can’t protect him from the whole world but it’s hard!

Looking for some support from dads who have experienced anything similar, thanks!