Not sure if this is a silly question or not...
I am using Drupal 8.
I was messing around with a sub-theme to a custom theme I am making. For now, the sub-theme has almost nothing in it and all the same regions as the custom parent theme.
When I swapped back to the parent theme as the running theme it dumped all my blocks into the header (ok, annoying but fine) but it also removed a number of blocks I had created.
For example, I had created several copies of the 'Site Branding' block with different settings which I then gave custom machine names to and styled with some twig template files. They were all missing but when I tried to recreate them I encountered a
machine name already in use error.
Is there a way to avoid this happening or having the machine names also be removed when the theme changes?
Ultimately, once the theme and base theme and an accompanying module are complete I plan to properly install and uninstall all these blocks programmatically but while I am experimenting I would like to be able to switch themes without breaking all my template files.