Thank you for your comment.
Yes, I confirmed that G28 is the command for setting a printer head to home position. But the screen of Reperier-Host has "home button", maybe a shortcut of entering G28, and I always use this button to do that. The home position is set as [X0, Y0, Z740] in printer setting.
As for "Having G90 and G1 in one line", you are right, it was actually recorded in multiple lines. I'd like show the printer log of that time, but I can't...
In my printer, although the bottom on the configuration is Z0, actual bottom is about Z200 because there are jigs and other components to fix the substrate.
I hadn't had such a situation before, so I have no idea why at all.
I would appreciate it if someone could give me some advice, even if it is only a possibe reason.