I have recently updated my gnuplot to the latest 5.4. I find problems with the labels and tics using the pngcairo terminal. For example, taking a simplified example from the official website
set terminal pngcairo enhanced font "arial,20" fontscale 1.0 size 600, 400
set output 'pm3d6.png'
set pm3d map
splot sin(sqrt(x**2+y**2))/sqrt(x**2+y**2)
I get a figure that looks fine, but letters in the labels and tics overlap in a strange way. Any idea about why this happens?