pattern of mirror element???

Hi
throw off a screenshot please. I try to help

this is with part design, as mirror is children so its not possible to deactivate parent and do pattern that's why like this. if you can detach then there is no problem

this is with symmetry, and you can utilize copy paste option to get other half

here is one thing I found out first use symmetry then give pattern after that use mirror and then deactivate symmetry and eventually delete it.

a) try a line array and a mirror

b) mirror the first detail and then the linear array on the sides

other
https://www.youtube.com/watch?v=e1i8XLUxdgw

If it is a feature or element, you can isolate it and do the pattern. It should work.