When you go to the Options from a page using the Frontend Editor it has no data. So when you save all what you entered before has gone!
Because the Backend Editor doesn't work properly (see other discussions in the Forum) and now this, it is almost inpossible to use SPPB 1.5.8 without loosing data.
We have a real bad issue now so i hope you can provide an update in the next days.
Don't ask for login i will not help. We are at least 5 users confronted to this issue now so you should be able to reproduce on any local machine using Joomla 4 and PHP 8.1 and above.
Thank you.
[UPDATE] Issue still exist in 5.1.9