When the spread is wide, the cause is usually mechanical and cheap to fix. Look first at compaction from the loader, then at a dip in the surface, then at floor slots blocked by old compost, then at air escaping round a door seal instead of going through the mass.
Raising fan speed on a leaking or compacted system simply moves more air along the easy path and dries the surface. Change one thing, run one batch, record what the spread did. A bigger fan bought without this evidence usually solves nothing.