Setting parallel processing to a size higher than the current preview resolution causes the node to stop working. Setting it to a lower scale and then turning it off, changes the scale of the node.
To repro:
Add aperture to a perlin. Set the aperture to an iteration of 3 or more.
Set the preview resolution to 1024.
open the parallel processing section and set the chunk size to 2048. = Effect stops working
Set the chunk size to 128 now and then uncheck "enable parallel processing" = scale changes drastically