The way MLP Lossless encoding will explain how this works, assuming you are playing it in 24/48 MLP. What do you see when you load the disc - does it go to a menu, or does it start to play track 1 immediately?
MLP Lossless outputsa decoded signal that is bit-for-bit identical to the input signal, and part of the process is the encoder will decode the stream & compare it to the original one to be certain.
Some streams compress better than others do, somerequire heavy tweaking and use of ReBit to make it all fit into the maximum stream rate of 9.6Mbits/second.
With Audio discs, this reading (bitrate) is both misleading & irrelevant.
PCM is a fixed rate.
DTS is a fixed rate in Legacy modes, like DTS, DTS-ES & DTS-96/24, but in DTS-HD MAS it is again lossless which means a variable bitrate and bit for bit identical output.
MLP is variable, and identical output.
Audio is therefore a constant, and bitrate meters pointless.
Don't worry - just crank up the volume.