Tried to sell just under 3k shares at .62, to buy more at a lower price. Had bid set at .62 when ask was .64. My order sat for about 2 minutes before it partially filled. The bid/ask stayed at .62/.64 for about 1 minute after the partial fill, then both b/a moved out of that range downwards. Why wouldn't they fill a bid to sell at the bid price fully, considering the order sat there at .62 while the b/s was .62/.64 with lots of air time to fill?