I always set my Dell pc in sleep mode and I don’t have any problems accessing internet.
Go :
Control Panel (on your left screen down write :Control Panel if you cant find it
When control panel menu open go :
Change settings, adapters or Internet adapters
You will find :
1.Ethernet
2.Wi fi
With your mouse : Right click and choose : Enable / disable in order to de energize disable temporarly pc adapters
Afterwards do it again Enable / disable in order to Connect making Enable again your pc adapter
The problem will be solved.