That's definitely an anomaly, I use vivado with ASIC code reguarly, very large designs and have not seen anything like this. I use vivado to elaborate and a analyse code intended for ASIC use as its better than other ASIC tools for that purpose. Once I'm happy with it in vivado, then I push it through design compiler, etc. Elaborating a deign that is 4 hours in DC synthesis is about 3 mins in vivado elaboration.