There's one specific field I fill in very often and for some reason Firefox is ''really'' keen on suggesting me two searches that I looked up more than a couple months ago, on a totally different site. I can't even remove these suggestions or add new ones. When I used Vivaldi, it'd learn what I insert (even if it'd end up suggesting tens and tens of options), while Firefox doesn't learn at all. For sake of an example, let's say that the word I use every day in this field is XYZ. Not even once was it suggested to me, I've only ever gotten the two in the screenshot below instead. And I can't remove them using the Delete key as some other article suggested. Speaking of which, I just noticed the same thing happen to the subject line in this form 🙃