Speaking of JLCPCB’s gerber interpreter/previewer, I face another issue: the X and Y board dimensions seem mixed.
For board dimensions the hint displayed suggests “X” being horizontal and Y being vertical; but after gerber upload these are switched (height (Y) x width (X) instead of proper width (X) x height (Y)).
Effectively, for “panel by JLCPCB” columns and rows are mixed. @atommann could you take look at this issue as well?
I’ve found JLCPCB’s ordering system infrastructure to be only somewhat stable. I’ve ordered a lot of boards from them - at least 50 orders - and, more often than not, there seems to be some sort of glitch. Often it clears up by retrying. Sometimes I have to wait a few hours. In the last 6 months, I can think of 3 times I had to wait a day or more.
The gerber preview is especially quirky, usually with parts placement/rotation preview. Once it didn’t work at all. I ordered anyway without correcting rotation and they sent me a preview PNG via email. Their techs made the proper corrections and the boards I got were fine.
I wish their systems were more reliable but I’ve always been able to get my order done.