Sharing screen problem

When I sharing my powerpoint presentation during Zoom meeting, I discover there are 2 or 3 black bars blocking the powerpoint which the participants cannot see all the ppt contents.  In this connection, I was told to change the video setting on the "share screen" - "Advance" - "Screen capture mode" from "auto" to "capture with window filtering", however it doesn't work (black bars still there).  So I changed to "secure share with window filtering" that all black bars disappeared but with such "secure share with window filtering", participants cannot see what I have written down on the whiteboard as well as powerpoint presentation under "annotate" - "text" function.  Please help and tell me how to solve this problem.  Thanks, Edmen