**System Information**
Operating system: Linux-5.3.0-55-generic-x86_64-with-debian-buster-sid 64 Bits
Graphics card: Quadro GP100/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.59
**Blender Version**
Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-06-11 09:02, hash: `rB665acd29039b`
**Short description of error**
When sculpting on an object with a multires modifier it works fine on every subdivision level. But once a single shapekey is added, the base shrinks on the lowes resolution so it's harder to target the vertices with the brushes.
**Exact steps for others to reproduce the error**
- Add a monkey object
- Use the grab brush and enable "Grab Active Vertex"
- Add a multires modifier
- Compare the difference in the white wires when the multires is toggled on/off
{F8608453}
{F8608455}