Sons fever came back from influenza

So my son is 18 months. Saturday night his fever spiked to 104 within 2 hours and he had a febrile seizure. It was very scary and we found out at the hospital he has Influenza A. The last day he had a fever was Sunday. He was home from daycare with me Monday and Tuesday and was doing great. He went back to school yesterday and had a great day.

Well last night (Wednesday night) he randomly woke up at like 3am with a fever again. Low grade around 101. I gave him ibuprofen to help him sleep. He had to stay home from daycare again due to the fever but it’s now been 7 hours since I first gave him that ibuprofen and he’s acting completely fine and the fever has not come back.

Is it normal for a fever to go and then come back with influenza? Or would it more likely be due to something else?

The doctor did say in the hospital that his right ear looked red but not infected and was probably just irritated from all the fluid. Could it have been from that?

I’m just a nervous wreck since that seizure, it absolutely terrified me