graduation curves - no automatic preview

[mirbachpictures]

hi all - we are working on catalina with the newest cloudversion.
problem:
if i work with "graduation curves" f.e. i get no preview! when i move the "gc-box" a little bit - than i get the preview. what should i do? new install?
sorry for my english ... 😉
ralf

[c.pfaffenbichler]

Could you please post a screenshot with the pertinent Panels (Toolbar, Layers, Channels, Options Bar, …) visible?