Diagnosis
The TV's Wi-Fi radio or antenna connection is weak or faulty. These TVs can also struggle with certain router settings or crowded 2.4GHz bands.
How to Fix It
First, restart your router and the TV. In the TV's Settings > Network, forget your network and re-enter the password. If possible, connect to a 5GHz Wi-Fi network instead of 2.4GHz for a more stable connection (if your router supports it).
If That Didn't Work
Use an Ethernet adapter. This model doesn't have a built-in Ethernet port, but you can use an Amazon-branded USB Ethernet adapter plugged into the TV's USB port for a rock-solid wired connection.
Heads Up
The TV's Wi-Fi hardware isn't the most powerful. Physical obstructions (like a thick wall) or distance from the router will affect it more than a phone or laptop.