The default behavior is to start charging immediately. If the station says sleeping, then the timer is still active.
You can try to disable manually
turn on advanced view
turn on developer mode
click the RAPI tab
enter the following command
$ST 0 0 0 0
That should set the start and stop times to 0.
I have an open evse "advanced" running FW 5.0.1 and WiFi 3.3.2. I had a start/stop time setup previously, and when plugging in our Pacifica, it would happily start charging when the timer hit each night.
With gas prices gone wild, we're using the EVSE much more, and I removed the start/stop time, however when plugging in the vehicle, the EVSE reports "Sleep" status until someone goes to the web interface to start the charge.
I don't have the button on the EVSE so this is not very user friendly. I've looked through the web interface and don't see anything to change behavior to "Start charging as soon as plugged in" vs. "Wait for someone to manually activate."