Hello

I recently bought a Phyllostachys Bissetii and have kept it in a container. It was dried out when I bought it but after watering it was doing really well and putting up lots more culms and lush green leaves, however, now it's having many leaves turn yellow and not looking as good.

Does anyone know why this may be? It's been in the same position since I bought it 3 months ago.

Thanks for any advice.