stencil display low quality

The stencil display is low quality; this happened on its own—I didn't make any changes to the settings. 
The texture resolution for the projection is 4K; the texture resolution in the scene is 2K or 4K (this doesn't affect the display). 
Viewport scaling doesn't help. 

Substance 3D Painter, version 11.1.3
Build 5196 - 464cbc573e735fa706a879f3a29107b6fc9865c7