Pivot and Pivot Unit Mode drop-down becomes white in the sprite property window on slicing sprite with Linear color space & OpenGLCore.

Steps to repro:
1. Open attached project.
2. Select Bird sprite and open in Sprite Editor.
3. Slice > Type > Grid By Cell Size .
4. Insert Pixel Size Vale = 100*100 > Apply.

Actual Result:
Pivot drop-down becomes white on slicing the sprite.

Expected result:
Pivot drop-down should not be white-out on slicing the sprite.

Reproducible in:
2019.3.0b1, 2019.3.0a3.

Working fine in:
2019.3.0a2, 2019.2.0f1.

Environment:
Windows 10, Mac 10.14 & Linux ubuntu 16.04 LTS.