My answer is very late, I know.
But my opinion is that if you have to pull up the LoCut of a vocal microphone (even a Beta58) to 250Hz – then something is wrong here!
In any case, I have never had to go above 120 Hz in the dLive since 2015.
Something is broken here. Either something is wrong in the dLive, or the speaker controllers are misaligned. I would take it to the service.