This is barely usable addon.Can be reliably used if you are browsing in only one tab and less than 40-50 minutes.This is high school software experiment level.There are much better addons instead of this try.Not recommended if you need reliable Pinterest button.
Things that would be useful to know: - what version of the extension are you using (current is 4.0.108) - what hardware, OS, and Firefox version (Mac, OSX 10.15.6, 79.0) - what page are you trying to save
