We did make code changes in the latest versions of LaunchBox for more performant EmuMovies downloads. That is easy to figure out, as it's in our change logs. Those changes worked just fine for a while with the EmuMovies servers, but something happened on EmuMovies' end that has caused lots of trouble as of late. The issues are likely exacerbated by the fact that we are now taxing EmuMovies servers more than we were before, but these issues were not caused by the recent LaunchBox code changes, which is clear because everything worked great for a while after the 12.8 release (which contained the more parallel downloads update).
Regardless, we're not here to place blame. We are looking for a solution, and we're working together with EmuMovies on it. We will have an official announcement/update out before the end of the day.