Styles marked "Always Hidden" keep appearing in the Styles Pane

I have clients who have yet to master the idea of working with styles. Consequently, I create templates intended to expose them to only a few styles that I ever want them to see when using either the styles ribbon or the styles pane.

Among the styles I want to always hide from them are Table of Figures and TOCs 1-9.

No matter how many times I explicitly hide these styles via Manage Styles, the styles will not stay hidden. All it takes for the styles to show in the Styles Pane is to create or update a table of figures or a table of contents. The only control I seem to have is choosing what to show on the Styles Ribbon.

(a) Why do certain styles keep reappearing in the Styles pane while others remain hidden?

(b) If reappearing styles in the Styles Pane can be prevented, then what are the steps?

Notes

• Tested on a PC in Windows 10 Pro with Office 2019 and 2010.
• "Automatically Update" style is disabled (checked out).
• "Only in this document" is enabled (checked in).
• The hide styles problem is reproducible in documents that use only built-in styles, that have custom styles, or a mix of those.

This is a very old bug in Word that Microsoft has chosen to ignore.

See these posts:

• Hidden TOC Styles reappear in the Style pane
  Posted in 2013, last entry added in 2016.

• Hidden styles unhide themselves in the Styles pane
  Posted in 2014.

The only workaround that was suggested was to add a VBA macro that will re-hide the styles every time that the document is edited. This might not be practical for you.