Re: Why so little progress?
Had you exhausted your linear progression when you stopped doing SS, or did you stop for another reason?
Stalling at that light a weight suggests inadequate food, bad form, failure to follow the program, or some combination of all three.
Whether to expect strength gains on Crossfit depends on your programming. Your experience with SS suggests a non-Crossfit issue, though. Tell us about your diet, please. Also, how tall are you?