it's the prime tower.
I couldn't find the setting in cura that changes, but in
%appdata%/cura/5.2/quality_changes/custom-printer.cfg
i changed
prime_tower_enable = True
to
prime_tower_enable = False
if you have grep installed, then you might run a recursive grep to find the proper file:
grep --color -rni "prime_tower_enable = True" %appdata%/cura