macOS Brave Helper (Renderer) at 250% of CPU after last Apple macOS security update

When I’m typing something in Facebook in particular, the renderer is taking a whole lot of CPU (Mac, macOS 11.6, 2019 Macbook Pro 16" with 32 GB RAM). The effect is that I’ll be typiing several words ahead of rendering for upwards of twenty-thirty seconds before the words appear on screen. Quitting and re-starting Brave seems to alleviate some of the delay.