@SomeoneElse as noted before this is not a bug, itâs the expected behavior. Itâs enabled by default to avoid the visual noise of quoting the full previous message.
If you reply to another message that is not the previous message or you just quote part of the message, you will always get the quote visible.
(If you want this to be a preference changed per user, you will have to open a feature request with discourse, since this is not an option right now)