You shouldn't need to run repair after changes, but running it can help to "encourage" the hub to find better routing for that switch. Results from a repair related to routing changes can take several days to a week to appear, so patience is recommended. Run the repair directly on the specific switch that you are trying to improve results from.
You probably need repeaters between the hub and the switch. Can you clarify what you mean by "...have Plus switches on both sides." Generally it sounds like you need more repeaters in your mesh, between your switch and the hub. You may need to add a Z-Wave repeater or two (e.g., Aeotec 6 or 7, Ring 2) or a Z-Wave plug (Jasco). After adding the repeaters, you can run a full repair on your Z-Wave devices, and then wait (could be a few weeks) for devices to see and use the repeaters.
However, you may find things settle down/sort out if you give it a few days. If you can handle waiting on the garage switch for a few days you could start w/that approach while you're shopping for Z-Wave repeaters/plugs to add to your mesh (or mess).