P: Adjustment brush values disappear

When using Lightroom Classic CC on my Mac Book Pro 15" with Intel Iris Pro 1536 MB, 2,2 GHz Intel Core i7, 16 GB 1600 MHz DDR3 and MacOS High Sierra 10.13, I have the following issue:
when I open corrective brush I can't see the values on the right. They disappear! 



I tried to delete preferences, I have deactivated GPU, de-installed and re-installed but no way.

The only way to resolve is to reduce image space, close LR Classic, re-open and it works....but it's quite a nonsense to reduce image space when you have to work with an..image!



So if I use the old version of Lr (named CC 2015) I have no issue. If I use the new one (Lr Classic CC) the issue can be fixed only reducing image area.

At the end of the story I had to reinstall the LR CC 2015 which works fine and in my opinion has a much better workspace, especially with a 15'' display.