Author here. I'm sorry things are not working out. I'd be very interested if you could open a report with the position involved. Sunfish move generation is test

Author here. I'm sorry things are not working out. I'd be very interested if you could open a report with the position involved. Sunfish move generation is tested pretty thoroughly, generating tens of millions of positions and comparing with other engines. But of course it's still young and glitches may happen :)