SUMMARY
After starting Okular none of the previous tabs are opened automatically. They have to be opened again manually. 
It would be a great advantage if it were possible to set the preferences so that the previous tabs are saved upon shut-down and then re-opened automatically upon the next start-up.

STEPS TO REPRODUCE
1. Using a Raspberry 4 and Raspbian, open Okular, open a number of PDF files in different tabs.
2. Shut-down Okular.
3. Start Okular, none of the previous tabs are opened automatically.

OBSERVED RESULT
None of the previous tabs are opened automatically.


EXPECTED RESULT
Previous tabs should be re-opened automatically upon start-up.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Raspbian OS.