Windows 10 V24.3
Open file (new or existing), Specs 10000x5000 px.
Zoom in to 64000%.
Select Pencil Tool. Double click settings (ensure color fill).
No stroke. Any color fill.
Draw complex, but small shape.
Problem: Shape is not held. Not enough anchors are added to keep original draw accurate. Add anchor should not be needed for quick workflow.

In my example. Drawing small lakes on a large world map. This changes the shape of my lakes, or I must make them bigger, but that will change the accuracy of my map.

This bug seems sporadic as sometimes I can create small shapes, but later, without making any settings changes, app is unable to perform as desired. I've even traced over previous shapes within the same version and it was unable to hold the shape.