Dashboard showing Presence Sensor as departed when I'm home

Hello guys,

I just set up my Smartthings presence sensor over the weekend and it's been working fine. now today even though I've been home since 11 am and haven't left and my sensor is with me on my key ring, why is it showing that it's departed?

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I clicked configure and saved a couple of times as I know sometimes that may be needed but it's not working for this

In troubleshooting this, I decided to open it up, pull the battery out "which showed 90%" even though it was only activated Sat when I pulled the tab. now it's showing 100% battery lol. but showing present again. so I will see how long that last.