This is probably something simple and obvious that I’m missing, but when I split screen, Sciv used to always default to the last (horz or vert) view. Now all of a sudden it defaults to vertical and stays there no matter what, including after I re-split horizontally using the alt key. Maybe I messed with some setting I can’t find?
What version of Windows Scrivener are you using?
The most recent version 3 for Windows. I always update on the very day it’s available.
I found out the problem. Under the Options–>Behavior–>Document Links–>Open clicked documents links in…, I chose In Quick Ref Panel.
For some reason that “disabled” the defaulting to last split view and opened any manual splits to vertical no matter what. When I went back to “In other editor,” the expected behavior returned.
I still don’t understand why opening links In Quick Ref Panel changed the expected behavior for manual splits, though.
Hi sammydix,
All posts related to the beta version should be posted in the beta forum. Always specify the version number to speed things up, otherwise the devs will have to ask. (Help > About) 
https://www.literatureandlatte.com/forum/viewforum.php?f=57
It seems like you might have figured out your issue. But if you still want the devs to see this, PM a mod and request them to move it to the beta forum.
Best,
Jim
Thank you. I’ll do that.