I received a customer-service message yesterday, requiring an additional $15 for an order that I had just placed. <span class="colour" style="color:rgb(34, 34, 34)">_You need to pay additional for your order._</span> _1.There are too many small slots in your file , it will take too much time to get it finished during the routing process._ Following up with JLCPCB chat/support has not clarified the issue either.  But apparently the "slots" are the spaces in the 2X5 panelization (which was created in EASYEDA), and "if there are too many slots, we might also charge you a milling fee." **Can someone explain the issue here, and what I can do to prevent this in the future?**  The red-arrows below are what the JLCPCB support agent pointed out.  It's extremely frustrating to have this surcharge added after my order is placed, knowing that the entire order (including other boards) will also be put on-hold until I pay hidden costs.