There are two accounts to check on your devices: the App Store account and the iCloud account. Apple maintains a service status page that is great to check if sync isn’t working. Sometimes sync problems come down to iCloud having trouble.
If you notice missing notes or updates, here are some troubleshooting steps you can try.
You can check when the last sync happened in the Sync section of Bear’s Preferences. With Bear Pro, Bear automatically syncs your notes and edits to all devices you don’t have to do anything.