In message , Bert
Coules writes
Tim Lamb wrote:

If the problem was the left hand edge in your picture, the board has
less support there because it coincides with a pipe run.

Actually it was the right hand edge. But see my post a minute or so
ago in answer to John Rumm for more details.

Yes.

Can you see if the other end of the flooring is tight to the
skirting/wall? It might be easier to adjust there than struggle under
the units.

--
Tim Lamb