Your ascendancy node, Relentless Pursuit, disables chill's effect on you. Because you're unaffected by slows, chill has 0% action speed reduction on you.
So with reverse chill, reversing 0% is still 0%. So you're gaining nothing.
When I was doing reverse chill I was wondering why every now and then my speed/chill magnitude would go to 0% for a few seconds. That's because I was using Fall of the Axe Silver Charm, which makes my speed unaffected by slows when the charm's active when I get inflicted with a slow/chill.
The unique charm has the same flavor text as your ascendancy node. So you'll need to respec those nodes into something else.