Nine times out of ten the missing column is not the puzzle — it is the print dialog scaling the page.
Check the paper size first
A4 is 210 × 297 mm; US Letter is 216 × 279 mm. A sheet sized for A4 printed on Letter loses height at the bottom — which is where the word list and the footer sit. Set the paper size in the print dialog to match the paper actually in the tray, and pick the same size in the generator.
Turn off “fit to page”
Browsers default to scaling content to the printable area. On a sheet that is already sized in millimetres, that scaling is what pushes the right-hand column over the edge. Choose 100% or “Actual size”, and let the page’s own margins (13 mm) do the work.
Margins, not borderless
Most printers cannot print to the edge. Set margins to “Default” or “None” in the browser and let the page’s 13 mm margin hold the grid. Borderless printing, when it exists, tends to clip the outermost border line.
Header and footer off
The browser’s own header and footer — URL, date, page number — overlap the bottom margin. Untick them in the print dialog’s “More settings” section; the sheet already carries its own footer.
Why the answer key is on page two
Each sheet is exactly one page and the answer key starts on a new page. If the key lands on page three, or the last word of the list spills over, the printer is scaling. Check the preview pane: the first page should end with the footer line, and nothing more.
If it still spills
Print to PDF first — “Save as PDF” in the same dialog — and open that file. If the PDF is correct, the printer settings are the problem. If the PDF spills too, tell us the paper size, the grid size and the browser; the page geometry is fixed, so it is a bug worth reporting.