They are both certified Z wave plus hubs. They should have the same range.
The issue is almost certainly one that comes up whenever you are moving devices from one hub to another without the option of using controller shift – – you can only add about two dozen devices at a time, and then you need to give the hub time rebuild all the network tables. Preferably about three days.
Meanwhile, your new network doesn’t look exactly like your old network. Not all the repeaters are in the same places, not all the tables are built. And yes, it’s a good idea to run the zwave repair utility to speed up this process, and it’s essential to run that utility if you are using older Z wave classic devices, not zwave plus devices. ( note that vera automatically runs this utility every night. Smartthings only runs it when you manually start it.)
Eventually, after you have all of the devices added to the hub and it has had time to rebuild all of the address tables and communicate the appropriate pieces to all of the individual devices, it should work exactly the same way as the previous one did. But that whole process can take a month or so depending on how many devices you had.
If the two controllers support controller shift, you can bypass all of this, which is what you do when you replace one vera hub with another or one wink hub with another. But that’s an optional feature, and smartthings doesn’t support it. So you’re just left with having to have patience until you get your entire network rebuilt.
The one tip I can give you as a former field tech to speed things up would be to move over all of the repeaters first, adding them in order from closest to the hub to physically farthest, so that you have laid down a good backbone before you start adding the battery powered devices. But that’s up to you. A lot of people prefer to work a room at a time, and there’s nothing wrong with that, it’s just going to take a little longer.
See the following FAQ. Start with post 11 in that thread, then go back up to the top and read the whole thread.
And here’s the FAQ on Z wave error messages: