If Private Internet Access (PIA) is blocking traffic to devices on your local network, you will need to enable local network access in the app. To do that follow these steps:
In the PIA app, click the three-dot icon (⋮) in the upper right corner and select Settings.
Go to Network and turn on Allow LAN Traffic.
After you enable this setting, you should be able to access devices on the same local network while the VPN is connected.