Tentacle to Tentacle Sync is not syncing

Steps

1. Power on first unit into master mode. It is flashing green.
2. Power on second unit into red flashing mode
3. Connected the units , master to slave unit, nothing happens. I’m expecting the red flashing light on the slave unit to sync and start flashing green like the master unit was flashing.

All the videos I see others on youtube doing shows exactly what I am doing. I am not sure what is wrong.