maybe a bugged interaction?

so i am playing Titan and i took ascendancy node Hulking from which gives 50% increased effect of small pasive nodes. then i took 2 maximum fire res nodes which give +1% max fire res. So i kind of get it, that if you take 1 it shouldnt give you +2% max res, but if you take two of them, shouldnt it give +3% max fire res? So is it a bug?