Sometimes tracking gets wonk and a reboot doesn't help. Pairing isn't consistent and need to go thru the re-pair shenanigans. I've found that this tends to settle things down.

1. Reboot
2. Make sure SteamVR is closed
3. Open file browser to "STEAM\steamapps\common\SteamVR\tools\lighthouse\bin\win32"
4. Run "lighthouse_console.exe"
5. This will bring up a console interface
6. Type "unpairall" into the interface and press enter
7. All controllers will be unpaired
8. Start re-pairing process again

Shouuuld be good to go!