Sumatra doesn't remember opened files

How to restore previous session?
Settings -> Options -> Remember opened files
But it don’t work.

It should be noted it says fileS that is it will only remember the files if 2 or more were open in the last session.
If you close with only one tab open it will not be opened automatically next time
(there is one exception sometimes used if self updating with only one file open)

That function relies heavily on a clean exit by SumatraPDF when it writes the currently open files to its settings file.

If the exe is closed by the user or system (e.g. a system update) in an uncontrolled fashion, then the file paths will not have been stored and session restore will not happen.
If the files are in a temporary or remote drive / cloud location then restoring a session can also be impacted.