You probably have a lot of CUE files. If you only have a few, you should convert them to single file per song FLACs instead. CUE files are an old solution to a problem that does not exist in MC. CUE files in MC can be tricky to deal with. Especially with a network based renderer. Single song files work better in general.
Though, if you are trying to get gapless playback of albums to work on a network renderer, that may not work at all, no matter what the format. Others here know more about that subject than I do. I've just seen reports that it does not work at all on some (many?) network devices.
If you can connect your renderer directly with Toslink, USB, coaxial digital, etc, that should work correctly for gapless playback. ...and it should work correctly with CUE files also.
Brian.