Many switch mode power supplies will increase the current draw if the voltage drops, that's why many of them will work on both 120 and 248V, while old school power supplies need a manual switch. I had a brownout once and thought my washing machine was broken because that was the only thing that stopped working (Until evening when I switched on the lights. That was back in the days of incandescents, oddly though led lights still dim with lower power, I don't know how they do voltage conversion).

We have so many cheap power supplies in our houses that it would not surprise me if at least some become unsafe if the source voltage drops too low. Being unsafe with only a slight drop is weird though.