Welcome! Thanks for including the console messages and URL, so many people don't!
Sorry, for this non-answer, but as much as I love Pale Moon, Facebook is one of the sites that I have decided to fall back to only visiting with Edge (which is my backup browser) because my experience of FB on Pale Moon is too unpleasant.
Maybe someone has a better solution, but I have found that for some sites, resigning myself to keeping a second browser open is the easiest workaround.
Sorry, for this non-answer, but as much as I love Pale Moon, Facebook is one of the sites that I have decided to fall back to only visiting with Edge (which is my backup browser) because my experience of FB on Pale Moon is too unpleasant.
Maybe someone has a better solution, but I have found that for some sites, resigning myself to keeping a second browser open is the easiest workaround.