Sorting by hot includes very old posts (Allow instance operators to trigger immediate rebuild of sorting, plus tune parameters on what is 'hot' and 'active')

Hello all! I am posting from my own self hosted instance, running 0.18.0, but this issue existed in 0.17.4 as well. When sorting posts from my subscribed communities by Hot, I will get a handful of newer posts, followed by an entire page or two of old posts going as far back as 4 years (not with new...