Hi,
From the picture, you can ping linkedin, while cannot access it. We will do more troubleshooting and try to fix it.
1. Try different end-devices and web browsers. Exclude the possibility that it’s the problem of one specific device.
2. Connect to the modem/gateway directly, by pass the C2300 to test whether you can access linkedin.com.
3 Change DNS to 8.8.8.8/8.8.4.4on the computer/end-device. You can refer to https://www.tp-link.com/support/faq/14/
4. Verity there is no filtering rule such as Parental Control on the router.
5. With computer connected to the router by ethernet cable, you can clone the MAC address. Go to advanced-network-internet-MAC clone.
6. Who is your internet service provider? And what is the current connection type of the router?
Besides, what is the current network topology?
Thanks in advance, and have a nice day.