As the name says, getting a affliction advances the Guardian Armor, but does nothing for the Wintertide Bulwark.

 

Leaving aside how bad an idea these quests were (100 afflictions?  on what is probably your tank?), I'm standing in a permanent trap and the armor is up to 78, while the shield is still at zero.

 

Hi ShivaX,

 

I've added your issue about Wintertide Bulwark's Stage 2 upgrade quest not progressing to our database for further investigation.

 

Thanks for posting!

Someone posted elsewhere that it apparently will progress if you either aren't wearing the armour, or the armour has already completed that stage.

If you want to try Thundercleese's suggestion Op just go down to the old city in Neketaka and frolic in the sickening fetid corpse stink. Takes about 5 minutes to get 100 afflictions.