Plaster cracking and becoming loose

I had the downstairs of my house re plastered last March, we noticed a couple of small areas where the plaster had blown initially but we had those fixed by a decorator and had it all painted once it had dried. The last few months I’ve noticed cracks appearing on every wall we had plastered, they have all started as hair line cracks which gradually get worse to the point we have patches cracking and pretty much falling off. Does anyone have any suggestions what could be causing this please? I’m unsure if I should contact the plasterer as it’s almost a year later. Many thanks in advance