Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 399.24
Broken: version: 2.80 (sub 74), branch: blender2.7, commit date: 2019-06-06 00:27, hash: rB8b2b79c2108b
Short description of error
Cannot sculpt with mouse after using a tablet - no effect on geometry
Exact steps for others to reproduce the error
Subdivide a default cube to comfortable sculpting level (or any mesh - doesn't matter).
Sculpt with tablet pen
Try to sculpt with mouse - no effect to geometry.
ADD: When switching on Dyntopo, there is some subdivision/collapsing, but still doesn't effect moving vertices
Graphic Tablet: 10moons T503