MNE MEG Interpolation

Dear MNE-community,

I am currently trying to interpolate some bad MEG channels with MNE.
Unfortunately there seems to occur an exception, such that the resulting
channels hold only zeros. Even when I try to interpolate only one
channel I get from '_field_interpolation.py:80' the log
'Truncate at 0 missing 0.0001'
As I understand it, this happens because the eigenvalues are all too
small. My data contains of 248 channels measured at ~291000 time steps.

I am currently stuck there, with no idea remaining. Can you give me a
hint what else I could try to get at least some interpolation for my bad
channels?

As suggested, I attached a minimal example in a github issue:
https://github.com/mne-tools/mne-python/issues/4377

Thanks, Christoph