"Auto Off" feature not working on Remstar Auto M

Greetings, all, a newbie here!

I don't think that the "Auto Off" feature is working on my Remstar unit The feature is turned on, but when I remove the mask, the blower NEVER shuts off. Is there a way to test/troubleshoot this? I use the unit in full auto mode, maybe i need to try it with auto turned off? Isn't the blower supposed to stop after it senses no paitent response after 45 seconds?

Thanks for any and all help!