So then again, back to the questions I asked about - let's pick one of those methods of "Launching Opus"... Double-click on the Desktop for instance, under the From the Desktop page in Prefs. What is it set to launch? The Default Lister, or a saved Lister Layout? And regardless of the un-expanded state of the Tree, does the "file display" show the intended starting folder (and is it "Computer" as that seems to be "selected" in your "Before" screenshot)?
In any case, before making any changes - maybe you should save off a "Backup" of the current Opus configuration... then, depending on whatever your Double-click on the Desktop is set to run (Default Lister or saved Lister Layout), I'd suggest you manually expand the tree, position the file display to show your intended startup folder, and then re-save the appropriate lister through either Settings->Set As Default Lister or Settings->Lister Layouts->Save This Lister..., and update the saved layout that you've got set to launch... if that still doesn't "fix" the tree expansion issue, I suppose it's "possible" that something in the recent update intended to fix the issue of "Opus changing folders by itself" might have broken something?
You could also try enabling the Expand 'My Computer' when Tree opens option in Prefs, since that's what you seem to want to happen anyway - and just see if that affects the issue, re-saving the layout doesn't otherwise fix it?
Edit Note: my URL was fubar'd, fixed it...