Since, as you acknowledge in the comments, “now good, now bad” is not really about time or specific moments, but just means “as many good moments as bad ones” — or more simply “as often good as it is bad” — I think it’s a good match for « tant bien que mal ».

The latter literally means “(doing) well as much as (doing) poorly”. But since those states don’t typically happen at the same time, it makes more sense to render it “doing well as often as poorly”. There’s as much of things going well as there is of things going poorly.

Put that way, you can see how close the expression is to “now good, now bad”.

(As you can see, I assume the translator reversed the order of the expressions, putting « tant bien que mal » first and « comme ci, comme ça » after, if indeed s/he intended to match them perfectly at all.)