I mix jungle dnb and have the same problem. I lot of the time you get 70-80 bpm as opposed to 140-160 - just as the kick drum pattern is not so defined as other styles.
Anyway, when importing your tracks and setting your cue points there is a x2 /2 button - I’d suggest just standardising on whether you go for the half bpm or true bpm for your library. I stuck with the half bpm values for my library before I realised it being an issue but I actually prefer it as the display is less busy with grid lines.
Hope that makes sense.
Also I believe you can edit the beatgrid and double or half tempo on the device - by using the ‘vinyl’ button…