exclamation point with wifi 5.1 lollipop

[squrrel]

Hello to everybody
Can anyone tell me why in the notification bar with wifi exclamation point?
every time you turn on the phone and do not use it so it is there when you turn it off and turn on the exclamation mark disappears.
Thank you for answer

[squrrel · Accepted solution]

Today I came out to extinguish the exclamation point
settings, power management, stamina, stamina mode to turn off the clock