Issue reconnecting once hub is re-powered on

I ddi multiple power cycles.

1. Transmitter powered off multiple times and it reconnects to the hum without issues
2. Hub powered off and on, the transmitter that was paired earlier is not able to re-connect. it's always in the waiting mode. Wifi is connecting properly. 

Pls let me know if I am missing anything.

regards,
Nandagopal