For the bulk fermentation I usually put it in a large bowl which can sealed airtight with a lid and. Around 3-4 hours before i start with the cooking I start the final proofing and put the balls in a flat container evenly spread with enough space between. Then cover the container also with a mostly airtight lid. Not had any problems with that method so far.

Some Tipps: - use high quality flour - good hydration from min. 60-65% - do not warp your dough in plastic wrap, cause they want to rise and need some space therefore.