Learn to read the parsers correctly.
In the overview of "damage taken", "damage absorbed" does not mean the amount of damage that you have mitigated on account of your shield and absorb rating. It refers to the damage that was mitigated thanks to absorb based shields such as those provided by Guardian Blade Barrier or Sage bubbles. The fact that you didn't have any absorb on your more recent night simply tells me that you didn't have a Sage healer bubbling you all the time like you did on that previous run.
I actually checked your damage taken tab and checked for your glance percentage: it's not zero, so, yes, you are shielding attacks. For your Writhing Horror kill it was 31.13% and for your final Dread Guard attempt it was 14.14% (yes, they're going to be less than your shield chance is listed as because that's percentage of total attacks shielded, which means Force/Tech attacks, which can't be shielded against, and dodged attacks, which preclude the need to shield, are counted in the same total), which make perfect sense considering those fights.
R Keep Calm and Carry On because you don't know how to read the parsers correctly.