Reminders not syncing across iPhone, iPad, and MacBook

I have a macbook, iphone, and 2 ipads. All are signed in to the same icloud account and all of them have icloud turned on for reminders. I am having issues with syncing reminders. They match on the macbook, one of the ipads, and also on icloud.com (My 3 "good" lists). My phone and second ipad have old reminders, but they will not sync with the other devices or with icloud.com or with each other. I have toggled icloud off, waited, restarted both devices and turned icloud back on. When I do that, the two devices update with the same old lists, but they don't match the other 3 "good" lists. Further, if I make a change on one of the "bad" lists, they don't sync with each other. The "bad" devices also don't show changes in shared lists, but the "good" devices do. To make things even weirder, if I make a change in my Notes app, that change syncs across all devices, so I know the icloud account is the same. Where else can I look?

[Re-Titled by Moderator]

Original Title: Reminders not syncing