Problem with masked arrays in histgoram filling ?

[MoAly98]

Hi,
I am trying to fill a histogram with a masked numpy array, but it seems like the masked values are aggregated in the first bin of my histogram, rather than not plotted at all. Is this expected behaviour?
The following example re-produces the problem

import boost_histogram as bh
import numpy as np
import awkward as ak
akarr = ak.Array([[20,10,5],[50,30,10,5],[50,40]])
akarr_m = ak.mask(akarr, ak.count(akarr,axis=1)>2) 
akarr_m = ak.mask(akarr_m, akarr_m>40) 
akarr_m
 >>> <Array [[None, None, None, ... None], None] type='3 * option[var * ?int64]'>
akarr_m[:,0]
 >>> <Array [None, 50, None] type='3 * ?int64'>
axis = bh.axis.Regular(10, 0, 100)
histo = bh.Histogram(axis, storage=bh.storage.Weight())
histo.fill(akarr_m[:,0].to_numpy()) 
>>> Histogram(Regular(10, 0, 100), storage=Weight()) # Sum: WeightedSum(value=2, variance=2) (WeightedSum(value=3, variance=3) with flow)
histo.values()
 >>> array([1., 0., 0., 0., 0., 1., 0., 0., 0., 0.])
akarr_m[:,0].to_numpy()
 >>> [-- 50 --]

As you can see intuition would say this histogram should only have one entry in a central bin, but it also picks up an entry in the 0th bin.

Thank you very much.

[MoAly98]

Any thoughts on this? At the moment I am working around it by converting awkward array to numpy and compressing them to remove None