I have problem with WiFi after sleep on my Macbook Pro 13 2015 Sierra. After sleep laptop is still connected to the network but i can't load websites, ping. I must wait long time or turn of and turn on wifi to resolve problem
The MacBook maybe connecting to wrong server while asleep. Check that you are connected to correct Wifi. I have this problem on my iMac. After waking, the internet was very sluggish if working at all. For some reason my computer switched its connection to another server without a password. I have to manually change it back to my own wifi.