"ss" wrote:

I mentioned that in post above but rethinking it maybe that the board is
slightly too long and is wedged in somewhere beyond the kickboard causing
it to bow upwards.

Yes, thanks for that: sorry I failed to acknowledge it earlier. With the
kickboards removed I tried to see how much (if any) gap had been left
between the laminate and the walls but it's very difficult to gauge.

Could it be that the weight of the units themselves is sufficient to prevent
the laminate's proper degree of expansion and contraction?

If so, maybe the answer is to remove the laminate from beneath the units.