NavigationSplitView/TabView change based on size class

Hello everyone! I recently started to think to introduce in my app SplitView for iPads instead of TabView which I currently have. But I would like to keep the TabView for iPhone and compact size class of iPad. I took my inspiration from a lot of Apple apps, like Apple Music or Photos. I was also looking at the Fruta app where similar technique is implemented, but that particular implementation does not fit my needs. The problem I’m having is that every time SplitView changes to TabView or vise versa the whole state of the app resets. I tried everything I could imagine, I couldn’t find a way to overcome this issue. The only thing I was able to fix is to maintain the same tab/list item selection, but everything else resets. Could anybody help me to resolve this issue? Thanks!