Neither of these articles says Germany's electricity supply is unreliable. There's no mention of power outages, or equipment damage, or anything like the power crisis in Texas power.
Instead, your citations say renewables are producing more energy than can be used.
That's a good problem. It can be solved by turning some of the supply off, or adding long-distance transmission to move the excess power to where it's needed.
But there's no hint of renewables causing instability or unreliability or power outages.
My source (a guy who works on the Czech power grid) says the Germans kind of abuse the Czech power grid in order to move their wind electricity from the north (wind turbines) to the south (industry). They even had to take measures on the Czech side to push some of that electricity back across the border.
