Startup with Last Session doesn't work
This is happening for a while now: When i open up Vivaldi after starting my mac, i always have to right-click on the tab-bar and use "Reopen Closed Tab" to get my last session. I noticed this is happening since Vivaldi starts in the background after startup. I didn't try disabling all extensions yet.
Vivaldi 1.5.658.56 (Stable channel) (64-Bit)
Betriebssystem Mac OS X
User-Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.100 Safari/537.36 Vivaldi/1.5.658.56
Befehlszeile /Applications/Vivaldi.app/Contents/MacOS/Vivaldi --remote-debugging-port=1338 --always-authorize-plugins --disable-translate --enable-blink-features=ResizeObserver --disable-begin-frame-scheduling --flag-switches-begin --enable-web-bluetooth --flag-switches-end --disable-smooth-scrolling
Ausführbarer Pfad /Applications/Vivaldi.app/Contents/MacOS/Vivaldi
Profilpfad /Users/[REDACTED]/Library/Application Support/Vivaldi/Default
Adblock Plus 1.12.4
Black Menu for Google™ 14.1.5
HTTPS Everywhere 2016.11.30
Just a Clock - the Hours 0.93.6
Just a Clock - the Minutes 0.93.6
Undistractify StackOverflow 0.1 (self made)
Do inactive extensions matter?
I know this is an old post, but I thought others may find this thread and find my response helpful.
I noticed this as well. In my case, the extensions ended up not mattering. I noticed, like you did, that Vivaldi would already be open when I started up the computer. I went to System Preferences > Users & Groups > Login Items and disabled Vivaldi from automatically starting up on Login and that seemed to resolve the issue.