Thank for your inquiry. First question have you check with Sling TV for support. Also are you also getting this frame dropped when you are watching on the laptop screen.
And also when you are streaming are using Wireless connection or wire connection.
Also do you have any type of firewall or antivirus install on your computer.
What driver version are you running on your system.
Please make sure you are running the latest drivers for your system from the manufacturer of your computer
Or you can also download the latest drivers for the graphics chipset.
Also verify with manufacturer if the HDMI port is with the Intel or the NVIDIA graphic chip