Operating system: Linux-4.15.0-65-generic-x86_64-with-debian-buster-sid 64 Bits
Graphics card: Quadro GP100/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 430.40
Broken: version: 2.81 (sub 15), branch: master, commit date: 2019-10-11 19:43, hash: rB60d02b336eaf
Short description of error
When selecting a Grease Pencil object, the annotation dropdown in the sidebar of the 3D Viewport disappears.
When the Annotation Tool is used Blender will deselect and remove the GP object as the active object, which brings the Annotation options back to the interface.