Can you try and check if disabling the BitDefender firewall fixes your problem. You can do that using the following steps, but note that this would disable the firewall (so you would want to reenable it once you identify if this fixes the problem or not):
1. Open network connection folder (run ncpa.cpl)
2. Right click on your Wireless Network Connection and select properties
3. Uncheck the box next to "BitDefender Firewall NDIS Filter Driver
4. Click OK
5. Repeat steps 3 & 4 for the Local Area Connection by clicking it & selecting properties & changing settings
You can try a sleep/resume now & see if the problem goes away.