A new study shows 87% still pass a fit test when they put a surgical over their 3M Aura N95.

13% did not, illustrating the importance of fit testing your respirator exactly as you will be wearing it.

That's my take on the study. Theirs is:

"Generic guidance on the use of N95 FFRs should consider the potential risk of increased failure when they are worn with an overlying face mask"

https://cidrap.umn.edu/covid-19/study-wearing-surgical-masks-over-n95s-can-cause-dangerous-leaks