Judging from listening experience on MW some years ago in Europe I think the bitrate chosen is too high. It is possible to use SBR and P-Stereo with much less bps and still get excellent results and nice sounding audio. At least in Europe the second biggest problem was interference from AM stations on the same frequency. It would be interesting to know how you hear this station from your location. I dare to say that you probably did not hear much with 8 dB SNR?
Please keep reporting. Unfortunately I never lived near enough to a medium-wave DRM station.