Hello,
Since "0/0" is the default value when you create entries ; that specific value is not read by the plugin and it display the text "below" the previous entry.
From TCPDF and FPDF documentations
SetXY
Defines the abscissa and ordinate of the current position. If the passed values are negative, they are relative respectively to the right and bottom of the page.
The unit is by default "mm" but that value can be override by your template. Since you're using a PDF as template, the plugin use "FPDi" to load your PDF and performs dynamic modifications.
Regards,