You spent an hour whipping egg whites, but the meringue spread out on the baking sheet like pancakes?
It is not fate that is to blame, but three factors: moisture, sugar and haste.
Start with the bowl. The bowl and beaters should be perfectly dry - wipe them with a paper towel with lemon juice.
Fat is the enemy of meringues: even traces of yolk in the whites will prevent them from whipping. Separate the eggs cold (so the yolk will not break), but warm the whites to room temperature before whipping.
Add sugar gradually: 1 tbsp every 30 seconds. If you add it all at once, the crystals will not have time to dissolve, and the meringue will crunch like snow.
Whip for 10-12 minutes until stiff peaks form. The mixture should stay on the whisk without dripping.
The secret to a glossy surface is a pinch of citric acid or vinegar. They stabilize the whites and prevent the meringues from "crying" in the oven.
Do not bake meringues in the rain. High humidity makes them stringy. If there is no other way, add 1 teaspoon of cornstarch to the whites.
Use parchment paper, not silicone. Silicone mats often leave a damp bottom.
Don't store ready meringues in the refrigerator. They will absorb odors and become damp.
For example, the first batch of meringue, whipped in a plastic bowl with fat on the walls, will definitely turn into an unpleasant liquid substance. But the second - in a dry glass bowl with citric acid - will hold its shape even after an hour in the oven.