"Show more" in Google search causes high Firefox GPU usage

Has anyone else noticed this? If I do a Google search and an AI response comes up, things are fine. But if I click "Show more" to get more details, the Firefox GPU process starts hogging my Macbook Pro:

PID COMMAND %CPU 1200 Firefox GPU 319.2

I do use uBlock Origin and NoScript addons, but these are disabled in private windows and this GPU thing happens with either regular or private windows where the addons aren't running. I only noticed this because eventually the fan will ramp up.