PropertyPanePropertyEditor has issue while editing

[DakSanjay]

Category

[ ] Enhancement
[X] Bug
[ ] Question

Version
Please specify what version of the library you are using: [v3.19.0]

If you are not using the latest release, please update and see if the issue is resolved before submitting an issue.

Expected / Desired Behavior / Question
When using PropertyPanePropertyEditor to update the webpart propeties I should be able to edit them at one place by editing the JSON format.

Observed Behavior
I have noticing that when I try to edit the property the ace editor window doesn't let me add append item correctly cursor moves inconsistently select entered letter on it's own & makes it difficult to edit. It allows import, export or copy pasting the whole JSON but get's very difficult to edit inline in the editor itself.