how to restart chrome properly without losing open tabs?

For a normal close, turn on Settings > On startup > Continue where you left off. Then quit with the three-dot menu > Exit rather than closing windows one at a time. If you close them one by one, Chrome only remembers the last window.

type chrome://restart in the address bar and hit enter. closes everything and brings the same tabs back. if something goes wrong anyway, Ctrl+Shift+T reopens the last closed window.