https://www.reuters.com/sustainability/climate-energy/ghost-machine-rogue-communication-devices-found-chinese-inverters-2025-05-14/

https://www.thetimes.com/us/news-today/article/china-solar-panels-kill-switch-vptfnbx7v

https://www.linkedin.com/posts/billhiggs_chinese-kill-switches-found-hidden-in-us-activity-7329866836760580096-B_3C

A few of the sources that China has kill switches in solar panels so they could turn off solar panels remotely.  Bet it's a safety concern so the American grid won't be overloaded.