“They don’t universally, investigate for yourself.”
If they don’t, then the experiment wasn’t set up properly. It’s not like this experiment hasn’t been duplicated countless times.
Besides, if you doubt Focault’s pendulum, there’s an even easier experiment that requires no fancy setup or electric motors, etc. Just get a basin of water and poke a hole in the bottom to demonstrate the coriolis effect. Then try to explain that away with a flat earth model (including why the water swirls in opposite directions depending on the hemisphere).
Lot of evidence to the contrary of that claim. Watched a lot of videos of kids on the equator scamming people with there demonstrations. Fun stuff.