This issue started after i installed Windows 10, while i still had CenturyLink DSL, which, on a good day, could get up to 6 mbps.
Ookla Speedtest shows 21 ms ping, 96 to 130 mbps download, and 11 to 27 mbps upload, all with Vivaldi and other programs running.
i also have an LG 4K smart tv...