Aura from rogue item not working

I've got a sharpening stone with a level 10 determination aura mod equipped on Isla in SSF ruthless, and when in a heist area with Isla (standing still next to her) there is neither an aura icon visible (with "show aura icon" option on) nor does my character sheet show any difference whatsoever in armour values.
What can explain this other than a bug?
thank you

Hard to test on ruthless but finally got Huck to appear in a map -- there a rogue weapon with aura (in this case haste) DOES work. It only DOES NOT work in Heist areas. This seems new to recent patches?