Problem with Curve in Lab color metod

[defaultlbfltupqpl84]

Choose A and click on the curve to set a point and then write a number in INPUT, after try to enter the number 0 in OUTPUT you see the boxes disappear.

Do you know this problem?

How can we solve?

Please let me know

Photoshop version: 22.4.1 20210518.r.211 7b18b4f x64

Massimiliano Crescioli

[c.pfaffenbichler]

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

Are you talking about Curves Layers or destructive Curves?