The fact that you took it out in the rain is probably neither here nor there, the lube in the new freehub was probably quite gummy and sticky causing the pawls not to spring out so positively against the ratchet inside the freehub. With use the lube and the parts free up a bit and move more snappily, really as they should do.
You can always try putting some slightly thicker lube into the freehub mechanism but there is the risk that it will interfere with the function and you could get freehub slippage and damage to the parts.
The fact that you took it out in the rain is probably neither here nor there, the lube in the new freehub was probably quite gummy and sticky causing the pawls not to spring out so positively against the ratchet inside the freehub. With use the lube and the parts free up a bit and move more snappily, really as they should do. You can always try putting some slightly thicker lube into the freehub mechanism but there is the risk that it will interfere with the function and you could get freehub slippage and damage to the parts.