Normal day to day cooling, I mean, obviously? Like if you have a system designed to operate in 25-30C(normal summer in most of Europe) but then you have a spike of temperatures going to 40C for a few days in a row, it shouldn't really be a surprise the system doesn't work in conditions it wasn't designed for? The compressor overheats and shuts down, especially if it wasn't installed in the shade.

Just like heat pumps for heating in winter are amazing for our regular mild-ish winters, but if you get a really cold spell and it drops to -35C, it's just not going to work at all to a point where it might not even start - you could also say "well what's the point of a heating system that can't heat in extreme cold".

The extreme is the keyword.