White ghost lines in Numbers

iMac 2019, Sonoma 14.6, Numbers 14.4

White ghost lines around merged cells filled with color

Created a spreadsheet that involves multiple pages. Page 1 is simple; no problem. Page 2 forward is a different table. I want the first and last rows to be filled with color, each page having a different color fill. Everything looks good on the screen, but when I print, vertical white ghost lines appear in the color fill. The width of the columns (about 5 characters) does not coincide with anything anywhere else in the spreadsheet.

The borders I've created are either 1.0 or 1.25 wide.

I have tried deleting the first and last rows and adding new ones.

I've selected the each row, gone to Edit > Clear All.

I can't change the border color to match the color fill because I can't find a way to get to those ghost cells. They only appear on the printed copy, not on the computer screen.

When I Unmerge the cells in either the first or last row, I see only the 2 columns that I created; neither match the ghost cells.

I searched the Community and it appears white lines have been a problem in Numbers for a long while.

Has the problem been addressed in either Tahoe or Sequoia?