As of Dolphin 23.04.1 it no longer remembers last opened folders n tabs.. Turning option off n back on does nothing to remedy the situation. Only downgrading to 23.04.0-3 fixes it...
STEPS TO REPRODUCE
1. Update to latest
2. Open different locations in different tabs
3. Close and reopen Dolphin, back to just Home folder.. Other tabs gone !
Session is forgotten...
To pick up from where we left off in previous session...
Linux: Latest ArchLinux
KDE Plasma Version: Plasma 5.27.5
KDE Frameworks Version: 5.106.0
Qt Version: 5.15.9
It also doesn't save your last session tabs etc if you open it trough the terminal, application menu or Panel.
IF you use the open dolphin shortcut (keybind) it opens the last session.
*** This bug has been marked as a duplicate of bug 469656 ***