Sometimes settings get changed to defaults during an update because the functionality they affect has changed.
To stop files from starting to play when added to Playing Now, uncheck "Options > General > Behaviour > Start playing when files added to Playing Now". If it is already unchecked, check it, click OK, reopen the Options dialogue, uncheck that setting, click OK and test again.
With the resorting of the Playlist when it is added to Playing Now, normally I would say check the Shuffle settings. But in your case, the MC26.0.30 version looks Shuffled, while the MC26.0.69 looks sorted by [Artist] or [Album]. Although it doesn't appear to be alphabetically sorted. More like it is Grouped. Maybe it is sorted by [Genre] or [filename], neither of which are in your image.
Can you determine what Playing Now is actually sorted by? That may help work out what is happening.
Are you sure that you got those image names the correct way around? Didn't accidentally swap the examples?
Generally when you add a Playlist to Playing Now, the sort gets set back to the default, which is to sort by Sequence number, and hence matches the source Playlist sort. If your example images are the correct way around, that doesn't seem to be the case.
I don't know of any way to permanently update the sort order of Playing Now. Sure, you can sort it by any column, and then Update Order to save the new order to the [Seq] field. But that doesn't change the future use of Playing Now. It always resets to Sequence.
BTW, it isn't the best idea to post images in PDF files, as they can have scripted actions. Use image files instead. Here is how:
https://yabb.jriver.com/interact/index.php/topic,125612.msg870781.html#msg870781