The different error codes have to do with different code paths for the game. The fact that they show up is just us being a bit more specific then the really vague HttpClientError or whatever messages we have before, but I don't know what all of the various codes themselves mean. That said, if you've found a repeatable way to make a certain error appear (maybe if you have a device with weak wifi signal you constantly see X error code in Y situation), please do report that in the
Bug Reports subforum, as even though developers rarely respond in there, we are constantly doing passes through there and adding new issues found to our internal bug tracking system, and consistent reproductions of errors is the best way to ensure we can find and fix the underlying problem that causes an error code.