Hi,
I am using SP Page Builder Pro 5.3.7 on Joomla 4.4.8 with PHP 7.4.33. The site and SP Page Builder were upgraded late last year but this is the first time that I needed to access the page(s) in question.
There two SP Page Builder pages which I get a blank page (i.e. the right pane of the screen is blank) when I try to edit them in the Frontend Editor. Both pages will load and display well on the frontend for site visitors.