Your setup put the Bee to go into deep sleep, but you didn’t assign a pin to be the wake-up pin. So the Bee isn’t waking up anymore. You need to either set the modem to be always on (ModemSleepMode = modem_always_on) or put a pin in for modemSleepRqPin (probably 23 if you’re using a Mayfly). If you want the modem to not sleep, you will have to use XCTU or manually send the commands to the Bee to turn off sleep mode.
NOTE: The next version of this library coming out soon will change this set-up.