If you cannot scan any Reolink camera (already has been connected to the network) in the LAN via Reolink Client (Win OS), please follow the steps below to check whether Reolink Client is allowed to pass through the Windows firewall.
Step 1. Click on icon at the bottom left corner on your PC, then tap on Settings -> Network and Internet –> Windows Firewall -> Firewall & network protection -> Allow an app through firewall.
Step 2. Click the Change settings button and tick on reolink client, then check Private or Public (optional) and tap on OK to save the settings.
Note: If it still doesn't work, please check whether you have installed any antivirus software on your PC, then close them and try again.