An error occurred while saving the commentCalvin Jay commented
InDesign 14.0.3 and Acrobat DC Pro 2019.010.20098 on macOS 10.14.6;
Paste text from annotated PDF document's comment panel into current working document;
Copy of a colour swatch appears in swatches palette;
Final clean-up before packaging includes deleting all copies of colour swatch.
Not a show-stopper, but very odd behaviour.
Fix is available in version 13.1 of InDesign.
Please update to the latest version available to you via Creative Cloud Desktop application.
Adobe InDesign team