Automatically suspend (hibernate) inactive tabs to free up system resources; This project is discontinued in favor of https://add0n.com/tab-discard.html
that's unclear why i should see the new session window if i did not restart my browser. even if i did, my Opera settings says "Continue where I left off" for "On startup" option.
when i selected "Options" in the Suspender icon context menu i got the options page loaded where i had a suspended page (another one, # 1 on the attached screenshot).
when i clicked "Open Recovery" on the options page i got only 2 pages (# 2). one of them is an opened page (# 3) but in suspended mode, another one is the page where options was opened (see above).
after Tab Suspender plugin update i see this page and got all suspended tabs closed in both windows: