Updating your DB and trinity should fix the problem (or at least reduce the items)
The reason is your loot profile (trinity) and by default, you use the weighted loot rules which don't really make much sense right now because of the scaling in ROS. Weighted loot works by scoring attributes and stats (for example, Int might be 20pts so before ROS 350*20= 7000 points whereas post ROS you see items with like 800 int and 800*20=16000 pts-- gets worse when you have items with Stat/Vit) and uses those bars on that second tab to determine where they end up. With Salvage all Rares, you should be salvaging almost all yellows, but blues (with like 1200 combined stats, for example) will still trigger stashing.
The way to fix this is to 1) Write your own rules, 2) Disable pickup of blues/whites/etc., or 3) Do what I did and just set all those radio buttons to None so it vendors everything that's not a plan or gem (I think None checked on rares with Salvage rares box checked as well crushes everything that's rare). This isn't a perfect fix but it works for the profiles I'm running while I try to figure out the rules...