Leaves keep yellowing and dropping, any idea why?

Is it possibly too dry? Or shock from a new environment? I bought this orchid about four weeks ago and since then it’s dropped four leaves (these are two of them), all in the same way. It’s dropping leaves from the bottom, they are yellowing and then separating very easily from the rest of the leaves. Nothing is mushy or rotting. Any advice is appreciated as this is my first orchid and I don’t want to kill it. It does look quite dry to me but the roots were similar to this when I first bought it so Im not sure, and don’t want to accidentally overwater it if it doesn’t need the extra water. Thanks!