If you cannot scan any Reolink cameras in the LAN(already connected to the network) on the Reolink Client(Win OS), please kindly check if the Reolink Client is allowed through the Windows Firewall with following steps:
Step 1. Enter Control Panel –> System and Security –> Windows Firewall page to click Allow an app or feature through Windows Firewall.
Step 2. Find the Reolink Client and click the Change settings button to allow the Reolink Client, then click OK to save.
Note: If you have installed any antivirus software, try to close them to check.