Fine filler forms cracks after plastering

Hello,

I wanted to ask here if anyone has an idea.

I applied fine filler on gypsum plaster. Now small cracks are forming. What could be the reason?

Did the compound not set properly or should I have primed twice?

I primed the wall beforehand.

Best regards

Dirk

Dries too quickly, had a draft or something?

Hi,

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