Issue with band_min in find_k

[DerekK44]

Hello,

I am having an issue with calling get_efield (and other get_Xfield functions) for certain values of band_min set by find_k.

In other words, if I first use find_k to solve for a set of eigenmodes:
ms.find_k(mp.NO_PARITY, 1/1.55, band_min=1, band_max=2, kdir=...)
and then I try to retrieve the electric field of the 2nd band:
E2 = ms.get_efield(2)
MPB returns the following errors from pympb.cpp (lines 1444-1452):
Must have 1 <= band index <= num_bands (1)
get_dfield must be called before get-efield-from-dfield!

However, if I set band_min=2 in find_k:
ms.find_k(mp.NO_PARITY, 1/1.55, band_min=2, band_max=2, kdir=...)
then getting the 2nd band's field profile (as shown above) works without any errors.

It seems that the errors occur when band_min != band number (value given to get_efield). Is this behavior consistent with the intended usage of get_efield and find_k?

Thanks for your help