We use DCMQI’s DICOM Segmentation Object converter. Developers of this tool, with close consultation with DICOM experts, concluded that it is not a good idea to use RLE encoding on top of bitpacking and so they do not support it, either for reading or writing. See some information here.
If you remove the RLE transfer syntax from your DICOM C-store SCP configuration and send the segmentation from BrainLab again then you will get the segmentation in an uncompressed format.