note 10 plus s secure not support

it's normal, because s secure not built up for flagships......we all flagship users have knox security service (3 layer security protection)...hence we have secure folder option...if bychance you install s secure from other 3rd party apps, then also it will not work.....NOTE:I know s secure and secure folder functionality is different, but according to Samsung policy you can't install it forcefully to your flagship ....s secure for midrange device, secure folder for flagships and A series ,m/s series.....only A80 and specific j series support both of that

Bro, I think you are talking about secure folder..not S Secure..just try once again.. swipe down notification panel and tap on secure folder icon..and follow all the required procedures..
or
just try normal phone reset settings
or
you should wait for another beta update to get this issue fixed..