If I’ve opened a (second) project in a session, when I next open scrivener it will open that project rather than the last one I was working on:
Start Scrivener -> Scrivener auto-opens Project A.
Open Project B (I typically do this through the recent projects menu).
Close Project B (File -> Close Project)
Close Scrivener (which closes Project A)
Start Scrivener -> Scrivener auto-opens Project B
Is this the intended behavior? I want Scrivener to open Project A at that last step (could it be auto-opening the last project opened rather than the last project closed?)
Currently this functions as you suspect, with the most recently opened project auto-loading on launch. We do have plans to change that however so that instead the program will auto-load any projects that were open when Scrivener was closed. If you find it more hassle than convenience with the current implementation, you can deselect this option in the top of the General tab in Tools > Options, then just manually load your desired project when launching Scrivener.
As an addendum, I’d like to point out that even if I close all of my projects, and then the template chooser pops up and it quit Scrivener by closing that window… it still opens the most recently opened document. If it’s to be consistent with what I’ve grown accustomed to on Mac, it shouldn’t open a project automatically if I quit scrivener without any projects open; instead it should bring up the template chooser.