Welcome to the world of system development. This has always been the case unless your customer is operating at a similar technical level and can formalize the requirements in your own language (or near enough). Your designers are able to formalize their requirements, but using a domain of discourse that your developers are unfamiliar with, and probably missing details your developers need because they, the designers, are unfamiliar with the domain of discourse your developers use. This always happens, no matter the field. Each group has their own domain language with its own notion and degree of formalization. As the developer, it falls on them to ensure their understanding is correct. The same would be said for non-software development efforts. An architect has the same problem with their customers, and a builder has the same problem with the architect.

It is certainly frustrating, but that frustration has to be overcome. Unless your customer (designers in your case) are intransigent and refuse to communicate when asked for clarification or refinement of details or feedback on a partial implementation, then this is a surmountable problem.