Hi! I'm new and this is my first post.
I'm running Plasma 5.24.5 on top of Arch Linux.
Running Firefox 100.0.2 64 bit
I've read the Arch Wiki, done several web searches, and the Firefox help pages, but can't find anything about my issue.
In settings, I have "Open previous windows and tabs" ticked; but when I close Firefox, and reopen it later, none of the previous windows and tabs are open.
I always have to restore them manually. (pita)
Could anyone provide any help??

Thanks,
Charles

You need to report this to Firefox, not a Plasma or KDE problem, and Firefox is not a KDE application either, so wrong forum I am afraid.