High Clock background usage on iOS 15

Ever since iOS 15.2 or 15.3 I believe I've been encountering random spikes of background usage for the default Clock app. It's not particularly connected to anything, since I usually have a single alarm scheduled (the one from Sleep Schedule) and I don't have any timers ongoing or anything that could justify it. I usually don't have the app open and ever since I've noticed it I've been a lot more careful about swiping the Clock app away/closing it, without any noticeable effect.

Once it starts running in the background, it usually keeps running until I restart the phone. Then it stops, and then at some point, days or weeks later, it happens again, and I haven't been able to pinpoint a reason.

It seems to be a software issue because I initially encountered it on an iPhone 11 Pro, and it has persisted after I upgraded to an iPhone 13 Pro Max. And I should mention that the 13 Pro Max was set up as a fresh device, without restoring a backup. In fact I also specifically deleted the 11 Pro backup from iCloud before setting it up. I also did a factory reset and a fresh reinstall of my 13 Pro Max in between that and now.

I've also encountered weird background usage from other default apps (Siri and Find My) but at least for those I could explain why they would be running, I have no idea why Clock would be behaving like this.