Hello my good friends

How are you guys doing and I hope all is well with you and your families.

I have noticed that my 3900 for the past month or so when I press and hold the green stb button to turn off I get options of
standby
power off
restart

So, I choose the option "Power Off" and the unit turns off and the red light shows up on the front face of the unit, but when I wake up in the morning, I noticed the red light is now green light and somehow unit is turned "ON" ?! and this happens every night and day? any idea why this is happening?

Much Obliged