A lot easier than you'd think.

You're right, LeraDraco69 it is a lot easier than you'd think - just need to do some lateral thinking and pay attention to the title. Thanks.

I think this puzzle was added to the website, either at the bottom of page 1, or on page 2. When this happens you always get fewer hits. The puzzles appear in the order they were proposed, not the order in which they were added to the website.

Really easy as soon as you get it..

as a little hint to start: the 4 of the first column starts at row 13 and the 5 starts at row 21

and it's symmetrical to one of the diagonal axis.

One unique solution. Thank you for the puzzle.