Qualitywings 787 low cruise speed

[Lil And]

I'm not sure what I'm doing wrong but when at crusing altitude I cannot go above mach .62 otherwise the overspeed warning will go off.

Clearly I've set something up wrong. I don't like to read the maunals, just kinda hope in the plane and see if I can get it off the ground - learn that way.

Have I missed a step? Have I put in the wrong cost index or something?

There should be a screenshot on my profile on FSX of what it's doing. I'm currently doing a nine hour flight so I don't wanna be going over .2 mach slower than what I can be ahahaha