I found this in the screen evs_block under \questmanager\engine\screens. The code block looks like this:
screen evs_block(cat, evlist, prefix=" {b}-{/b} ", completed_suffix="{image=completed}", progress_suffix="{image=in_progress}", unknown=_("? ? ?")):
text " "+__(cat)+" ":
style "category_style"
the text ""+__(cat)+"": is where the ~ should be in your block. I just removed mine but left the category area in case I wanted to change it around later. I hope this helps!