Which is bad, it's a market and infrastructure failure. Negative prices are to get generators to turn off.
A new feature on solar inverters is curtailment mode so they can be remote shutdown when the grid goes negative, since if you're on wholesale energy pricing you'll be charged if you keep driving the grid.
If the market is being driven negative then it means there's an oversupply. Which means overall the price of electricity is higher then it should be - negative prices have to be compensated by higher positive prices at other times, and reduce the return on capital to build new power infrastructure of all sorts.
Turning off productive solar panels is wasting power.
The negative price can also be thought of as paying people to use the productive solar panels rather than turn them off, it's a two sided market that drives demand to times of clean and cheap energy, which lowers costs for everyone.