Operating system: Windows-10-10.0.15063-SP0 64 Bits
Graphics card: Quadro P5000/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 382.59
Broken: version: 2.83 (sub 0), branch: master, commit date: 2020-01-12 16:27, hash: rBf6aac92ab828
Short description of error
Added a mesh and deleted the faces, converted to a curve then again to greasepencil, enabled the fill option to create a grease pencil cube. Fill doesn't work properly.
all default meshes don't fill properly when converted to a curve then greasepencil.
Exact steps for others to reproduce the error
Add Cube --> Edit mode -->delete only faces --> convert to --> Curve from Mesh/text -->convert to --> grease pencil from curve --> material properties -->New --> surface-->enable fill--> Doesn't fill the 6 sides, it's a deformed fill.