here is a possible issue that I can't solve by myself or looking on the forums
Operating system: windows 10
Graphics card: rtx2080
Short description of error
adding a simple default shader (in the shader mode) to an object slow-down sculpting reactivity drastically, removing the shader doesn't re-establish the sculpting reactivity, saving the scene in this state preserve the slowness of the painting tools when reopening.
This is visible on a relatively heavy model (more than 3 millions triangles) but even if the painted object is in a default fresh scene, the issue is 100% reproducible on my computer.
Another little issue : brush circle doesn't appear in sculpting windows unless you click on another tab mode and entering again in sculpting mode.
Exact steps for others to reproduce the error
you can reproduce the issue on a subdivided box (clearly visible from 2 millions tri and worse with 3 millions and after) and using any sculpting tool before and after adding a single default shader (what ever the rendering engine you use).