Hi @matelon, try first disabling all plugins, themes and css snippets you may have in your vault. Then activate them one by one to detect the cultript.
I think it could be something related to whatever is adding the list folding functionality.
Happy you found that solution for you! I applied your code temporarily and realized that I removed that setting at some point to meet my preferences for how to handle line breaks.
In general, I prefer less space between lines; and I use a header or a --- divider on the occasions where I want separation between bulleted lists.
Happy again that you found the solution that best suits you though, that must have been quite the css exploration!