Lag with area of effects

Hi,
I'm not sure how to address it or how it can be resolved, but here's my issue.
During boss fights, I get lag. I get out of aoe, on my screen I am totally out of it (my husband even looked at my screen and agreed) but still take the damage or die. Titan Hard was pretty aweful with those problems.
My husband has no issues, we have pretty much the same computers, I'm wired to the router and when I check the ping with Montreal server, it shows an average of 27 ms, which isn't bad at all..