Every openHAB instance has a Network Security Key that’s generated when you set up a controller. You can see it under the controller thing if you click “Show advanced”.
The problem is that your securely included locks are looking for the old key from OH2, so they refuse to take commands from your new OH3 system.
If you have a backup of your old system, you’ll want to restore it and get the key from PaperUI. Then you can paste that into your OH3 system, remove the locks, and add them back. That worked for me when I upgraded.
If that doesn’t work or you don’t have a backup, you’ll have to fully exclude your locks from the controller and then securely include them again so that they get the new security key. Since secure inclusion can be difficult, I recommend trying the backup first.
Here’s a discussion from last year that’s identical to your issue. Unfortunately, the original poster wasn’t able to get it working after they copied the network key, so they had to exclude and include.