Lines/bars appear when using levels

[11elements]

Whenever I try to use levels adjustments, short, horizontal, grey bars appear at random on the image. See the attached crop with one appearing beside her teeth.

[stokerg]

Hi @11elementsand Welcome to the Forums,

Can you try clicking Edit>Preferences>Performance and disabling openCL at the bottom of this window, restart Affinity and then try this again and let me know the results