ADB issue while connecting through WiFi
First connect adb with usb then make connection in same network. Don't disconnect adb over usb. Now execute adb over tcp. If you are forwarding to some port means you have to disable firewall on that port. To disable firewall on port if you use linux. Open terminal or press ctrl+alt+t, Then try with these commands

ufw allow port_number


here replace this port number with forwarded new port number.

If you are windows user
this thread may helpful for you.
After allowing this port restart your adb server. Once the device is connected over wifi then you can remove your usb from your pc. If you need to know about port forwarding in adb see this thread.