Sleep Wake function not working

Hi all, After updating to the new mojave on my MacBook pro, the sleep wake function on my mac no longer seems to work. So if i leave my mac for a while or put it to sleep then come back 1 hr later i was able to just tap the keyboard and it would wake again on the same page or app i was on.

Now when i wake it i get the spinning circle and then it reverts back to the log on screen where i am unable to type in my password in to log back in, so I have to restart it every time now. Its really quite annoying - can anyone help?

thanks anna