Mold Issues When Drying Split Bamboo

This is James Khan from Northern Bangladesh, Asia. We are working with Bamboo for few years and we do natural sun drying in dry/cold season (Oct to April) for our split bamboo. But we are facing issues of mold/fungal attack during drying and even production during monsoon. So we suspect that our natural drying under direct sun did not season the materials well and moisture locked inside.

May I get your kind suggestion to drying split bamboo? Direct sun drying/ indirect sun drying/process/ techniques etc. Thanks.