I’m having an issue with Table Row borders. All seems to be working great up to rows 250-260 in all tables. Although my script indicates the task is getting done, the output shows no borders after said rows. Is there a strange upper limit or something? Data will write to the table as it should, cell merging will happen as it should, just the borders will stop being drawn.

Running python-docx v1.1.2 in python 3.9.2.

Just so it’s here, here is my function that I’m calling, which again is function all the way up to these rows:

def set_whole_row_border(table, part_row):
    tbl = table._tbl
    rows = tbl.getchildren()
    for this_row in rows:
        if isinstance(this_row, CT_Row):
            cells = this_row.getchildren()
            if this_row.tr_idx is part_row:
                for cell in cells:
                    tcPr = cell.tcPr
                    tcBorders = OxmlElement('w:tcBorders')

                    top = OxmlElement('w:top')
                    top.set(qn('w:val'), 'single')
                    top.set(qn('w:sz'), '12')
                    top.set(qn('w:space'), '0')
                    top.set(qn('w:color'), '#000000')
                    tcBorders.append(top)

                    bottom = OxmlElement('w:bottom')
                    bottom.set(qn('w:val'), 'single')
                    bottom.set(qn('w:sz'), '4')
                    bottom.set(qn('w:space'), '0')
                    bottom.set(qn('w:color'), '#000000')
                    tcBorders.append(bottom)

                    tcPr.append(tcBorders)

    print('border done for row', part_row)